682 Ogre / Frederic

514 Anton Slater

454 Harrison Wells (Earth-TUD2)

432 John Deegan

416 Harrison Sherloque Wells fourth ex-wife (Earth-TUD10)

509 Cassandra Savage

I won't add any new clues just yet but cleaning out the dead clues.

Letters/numbers found so far: ABCDEFGIJKLMNPTVWXZ2345780
414. Comics (has different code name with same meaning); assassin; possibly Green Arrow; his team was allied with major villain BEA* [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPTVWXZ245780]
415. Original; spy; proficient in air radio terminology ALAN D*RAND [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
417. Real person; presumed watercolourist if same as real version; sister of a famous female novelist CA**ANDRA A**TEN
418. Original; police detective; took part in getting innocents convicted *T* D*NNELL*
419. Original; unrevealed; because friends with a cast character after they moved to their town for a time LA*RA **FFMAN
420. Comics; criminal; All-American Comics; created giant version of recurring toy character *ARG*N T*E **RCERER
421. Original, but related to comics based character; actor, secret society leader; great-great-grandfather of cast character *ENR* *TEIN
423. Earlier character this continuity; unrevealed; read a poem about bread *.P. WELL* (EART*-25)
424. Comics; police detective; The Flash; partner (in the job sense) of cast character FRED C**RE
428. Slightly earlier (same episode) character this continuity; arsonist; mistaken for visiting counterpart from another Earth EDDIE *LICK (EART*-#)
429. Comics; head of IT, former hacktivist; OMAC; helped create (computer) super-virus with roommate and a cast character M*R*N F*RE*T
431. Real person; jazz guitarist; killed by minotaur in erased timeline DJANG* REIN*ARDT
433. Original; accountant; actions led to extortion, kidnapping, and murder *AR*LD BACKMAN
436. Comics (individual based on a race); presumed criminal; Guy Gardner: Warrior; sentenced by main character's mother T*RM*CK [LOCKED; Both remaining letters the same; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
440. Original; unrevealed; mother of cast characters NA*REEN TARAZI [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
443. Original; corportation founder, inventor; main villain of a season; likes to sing BI***P
444. Original; doctor, metalsmith; outfitted cast character in Samurai armour IC*IR* *AMA**IR*
445. Original, though name evokes movie characters; high school graduate; wrongly believed to be a killer in one timeline FREDD* ME*ER*
446. Original; unrevaled; fostered alien child for a time DANA F*RD [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
447. Comics (slightly different name); high school student; Steel; from another Earth and has no counterpart on main Earth due to counterpart parents never getting together NATALIE LANE  IR*N* (EART*- T*D22)
449. Original; personal assistant/double agent; fired by boss for spying on behalf of boss' mother ALANA (L-C*RP) [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
452. Comics (comics version has different real surname); field supervisor; The Flash; has superhuman strength, etc.  F*ERZA /  ALEXA  RIVERA [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
456. Original; prison warden; fired for misuse of prisoners W*ATT K*TE
463. Apparently original, though related to real person; unrevealed; uncle of famous musician L*CI*** PRE*LE*
464. Earlier character this continuity; unrevealed; in prison camp for being Jewish FElICIT*  *M*AK'*  EART*-X  D*PPELGÄNGER
466. Comics; none; Convergence: Superman; erased from existence and replaced with much older person of same name  J*N*T*AN KENT (*RE- CRI*I*)
468. Comics; prison warden; Bite Club; seen mainly in darkness, hinting she might be a vampire as per the comics version DEL T*R* [LOCKED; both remaining letters the same; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
471. Comics (indirectly/different first name); terrorist; Supergirl; counterpart of hero/former cast character  T**M*N / WINN  *C**TT (EART*- T*D##)
474. Original; judge; precided over trial of a cast character (but not main character)  B*ACKETT [LOCKED; characters found at time of locking: BCDEFGIJKLMNPRTVWXZ245780]
478. Comics (indirectly); unrevealed to the extent applicable; Action Comics; counterpart of sorts to relative of cast chatracters ALEX  DANVER*'  M*T*ER (*B*IDIAN  PLATIN*M)
479. Original; criminal gang leader; used alien tech in crimes C*ET MINER [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
480. Original; government agent; recurring ally of cast characters  VA***EZ (EA*T*-38)
481. Original; high school student when last seen; close friend of cast character during teen years J**IE
482. Original; district attorney; questioned main character during his or her trial ALEXA VAN **EN
485. Comics; criminal; Robin Annual; could morph hands into blades RAZ*R**ARP /  RAELENE  **ARP
487. Original; unrevealed; villager in an African nation  F**IN**LA
490. Original; crime boss; killed by gaseous villain ArAZ  DARBIN*AN [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
491. Original; government agent; hunted a villain who killed him  RE*N*LD*
492. Original; unrevealed; killed by parasitic villain *NNAMED  **APE-**IFTER
493. Original; high school student when last seen; cast character secretly has a crush on her as a teen  VICKI D*NA**E
494. Original; slave turned spy; tasked with stealing battle plans from an enemy *ENR* *C*TT
496. Earlier character this continuity; unrevealed; resides in bottled Earth A*ALA'*  EART*-T*D#7 D*PPELGÄNGER
497. Original; counseling director; disliked for strict methods in running camp PA*LA C**PER
499. Earlier show (indirectly); timeline protector; The Secrets of Isis; counterpart of sorts of cast character, though unlike main version has tattoos ZARI TARAZI (R*B*T) [LOCKED; both remaining letters the same; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
500. Original; restaurant co-owner/waitress; harassed by someone wanting protection money JENN* R****
504. Real person or comics depending on how you look at it; unrevealed; Flash Comics; resident of Iowa City during some period of the 20th century K**F*'* ##4# REINCARNATI*N
506. Comics; presumed criminal; Nightwing; helped stop a drone strike T*R**E
507. Comics going by character in general, earlier show going by specific name; founder/CEO;  Superman's Girl Friend, Lois Lane but this name from Smalllville; father of major villain  LI*NEL L*T**R
508. Real person; senator; betrayed his best friend; this betrayal was chronicled by someone else in this collage in the real world BR*T**
510. Comics; museum owner/future currator; The Flash; will eventually curate a museum devoted to a main character DEXTER M*LE*
511. Comics; CEO; The Power Company; had nannite-created powers BI*MAX /  JACK *P*EER
513. Original; server; played Dungeons & Dragons with cast character MARC* [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
520. Original; unrevealed; childhood bully of major villain JE**E FEDERIC*
522. Original; nation's President; gave a speech on a late hero **A*
532. Comics; military sergeant and bomb defusal specialist; The Fury of Firestorm; could spontaneously combust objects upon physical contact PLA*TI**E /  BETTE *AN* ***CI
534. Original; student, also vigilante in one future; legacy villain in erased future CiCADA /  GRACE GIBB*N*
536. Comics (indirectly); timeline protector; Justice Society of America; has super strength and durability NATE *E****D (R*B*T)
537. Earlier character this continuity; posed as police officer; replaced somene captured in an elevator DAI** K*RBER (MIR*RVER*E)
539. Original; investor; invested in an attempt to make a museum *LGA [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPTVWXZ245780]
541. Original; government agent; electrocuted underwater ALEX ***TT
542. Original; mercenary arsonist; crew fought off two superheroes before being defeated CAMER*N ABRAM*    
544. Comics (indirectly); company owner; Justice League of America ; husband of counterpart of main character's mother MALC*LM MERL*N (EART*-2)
545. Original; army leader; alien who helped try to take over the Earth T*E C*MMANDER
546. Original; slave; whipped for accidentally burning cloth prior to being freed by heroes MAR* [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
547. Original; actor; posed as father of cast character RAND* **ARPE
548. Original; being specific would reveal most of the answer, but some sort of mayor aide; affected by some sort of outbreak at City Hall C*IEF *F *TAFF IN NATI*NAL CIT*
550. Original; controlled demolitionist, terrorist; accidentally killed children in building detonation ALEX FA**T
551. Comics; reformed criminal; The Flash; powers include telephathy, empathy, fear inducement, illusion inducement P**C* /  BA**IR MALIK
552. Original; housewife; wife of major villain L*DIA L*CK***D
553. Original; security agent; ex-husband of cast character T*LER [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
554. Original; government agent; hunted a villain who killed him T**NG
555. Original with some comics elements. This one's a bit complicated. In one sense this is a separate character than one seen earlier (which is how Arrowverse Wiki originally treated them as) but subsequent evidence (from after I created this collage) places them more as the earlier character themself (previously found); adventurer as such; Flash Comics (comics elements); if separate character, they share DNA of a major character mixed with an alien's *ARA LANCE (CL*NE)
557. Original; high school student; ex-boyfriend of cast character *EAN *MIT*
558. Original; likely student of any; son of a later superhero AKI* *AMA**IR*
561. Original; bartender, alien rights activist; ran group therapy sessions for aliens *I*NA B*RNE
568. Comics unnamed, radio show named; vigilante; Action Comics, named in The Adventures of Superman; killed by counterpart of main character JAME* *L*EN'* EART*-X D*PPELGÄNGER
569. Original; drug dealer; sold drag that turned people into rage monsters KE*IN **GGIN*
573. Comics (gender swapped/different real name); cultural anthropology professor turned criminal; The Fury of Firestorm; could animate objects BLACK BI**N / MINA C*A*TAN
574. Original; asylum inmate; has drooling problem ABRA*AM [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
577. Original; housewife/restaurant assistant; supplied the burgers' secret sauce R**NDA BEEMAN
578. Original; pastor; lived in Odessa, Texas in 1925 P**ELL
579. Original; science centre owner; secretly worked for season main villain D**G MILLER
580. Original; unrevealed, likely student if any; has alien for a pet ALANA (*PIKE'* **NER)
581. Original; gangster; skipped town to avoid main character MARC** *T*CK*EIMER
587. Original; high school music teacher; surname is a music term **ARP
588. Comics; Linguistics and Semiotics teacher, cultist; Worlds' Finest; left one cult but cultists tried to force her into another cult TAN*A *PEAR*
592. Real person; phone operator, inventor, actress; film career drerailed by time-displaced woman *ED* LAMARR
593. Original; army officer; led soldiers in capturing cast characters MIK*AIL ARKADIN [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
595. Original; nation's president; killed during alien invasion T*AVELE* [LOCKED; both remaining letters the same characters found at time of locking: ABCDEFGIJKLMNPTVWXZ245780]
596. Slightly earlier (same episode) character this continuity; unrevealed; killed a cast character's father in a drunk driving accident BEETT C*LLI** (EAET*-2)
599. Original; unrevealed; attended daughter's wedding but ended up making out with the would-be groom M*. *INCLAIE'*  M*T*ER
600. Comics but gender swapped; criminal; The Brave and the Bold; has mind control and telekinesis X*TAR [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
603. Comics; unrevealed; Batman: Shadow of the Bat; born with mental illness and prone to attacking others AM*GDALA /  AAR*N *ELZINGER
604. Comics (gender swapped, so slightly different real name); criminal; The Flash; can induce vertigo T*P / R**A DILL*N
607. Comics; lab assistant; The Fury of Firestorm; cast characters unnerved by his resemblance to a super-villain  *ENR* *EWITT (EART*-2)
608. Comics (likely different real name, Arrowverse version missing first word in code name); criminal, weapons dealer; The Flash; can create box-like force fields BL*CK / VANE**A JAN*EN
609. Original; scientist; alien with thorns on his forearms R**AN V**E
610. Comics; serial killer; The Fox and the Crow (real name), Green Arrow (code name); obsessed with main character's earliest vigilante persona *TAR CIT*  *LA*ER a.k.a.  INMATE ##22 /  *TANLE*  D*VER
613. Comics; assassin, CEO; Young Justice; created an enormous destructive tidal wave RIP R*AR /  R***ELL  R*GER*
614. Original; newswoman; interviewed counsellor on anti-vigilantism bill JANE W**D*
616. Comics; vigilante; Batwoman, but inspired by character from Detective Comics; only seen in a photo KATE KANE (EART*-##) [For this one I'm locking the numbers as this one's now too easy to guess otherwise]
617. Comics; scientist; The Brave and the Bold; developed a device with the power to create a man-made earthquake BRI*N MARK*V [LOCKED; both remaining letters the same; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
618. Original; money launderer; worked for crimelord in flashbacks P**TR FRIEDKIN
623. Original, though name might be a nod to two real life people; business founder, investment magnate, philanthropist, socialite; held a fundraising gala where she spokie with cast characters looking for her son T*ERE*A MERKEL
624. Original; unrevealed, likely student; cast character's first cousin once removed C*RI*
625. Comics; nuclear truck driver; The Flash: Iron Heights; has power to emit dangerous levels of radiation FALL**T / NEIL B*RMAN
626. Original; crime lord (code name refers to another occupation that he doesn't actually have); took over part of town after an earthquake T*E MA**R /  XAVIER REED
627. Original; police officer; killed by cast character in self-defense BR*CK [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
628. Original; cultist; part of a coven wishing for old deities to be worshipped FEI*A [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPTVWXZ245780]
631. Comics (indirectly); posed as chief of police; The Flash Secret Files and Origins; replaced main version of the character DAVID *ING* (MIRR*RVER*E)
632. Original; accountant; attempt to retrieve money extorted from a mayor JA* REIM*D*K
636. Comics (comics version's first name unrevealed); technology firm employee; The Flash; fired from organization and then killed for being whistleblower GENE ***KK
637. Original; arms dealer; came to town to sell a shipment of stolen weapons but was interrupted by cast character LE* M*ELLER
639. Comics (indirectly); timeline protector; Hellblazer; mistakenly believed herself to be the real version A*TRA L*G*E (R*B*T)
642. Comics (name with slight capitalization difference from novel); scientist; Action Comics, name from The Adventures of Superman; similarly named character (missing one letter) from same creators from New Adventure Comics; father of major character J*R-EL [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
643. Original; bus driver, criminal; stomach slashed by major villain KEI**A M**RE
646. Original; unrevealed; gained powers in an experiment JA*PEE T**NE*
647. Original; criminal; right-hand man for recurring villain **ECK
648. Comics (prototype from magazine); vigilante; Action Comics  (prototype from Science Fiction: The Advance Guard of Future Civilization); villainous counterpart of a superhero **PERMAN / KAL-EL (EART*- T*D22)
651. Original; councilman; ally of major villain K*LLEN*
655. Original, but resembles character based on comics; mobster; resembles character from Justice League of America; seen in artificial reality C*TTER M*RAN
656. Original; doctor; assigned to care for main character RAFAEL R*D*IG*EZ
657. Original; police officer; provided superhero with intel AN**N
662. Comics; drug dealer; Green Arrow and Black Canary; attempted to murder a police detective *EAN **N**
663. Original; TV anchorman and news reporter; reported on a major first episode story  MERRITT DAVI* [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
664. Comics (different real surname); student; Flashpoint; had the power to harness electrical energy BLACK**T / FAR*** GIBRA*
666. Original; named after real person but not a true counterpart; criminal; kidnapped major character's son J**N B*RNE
667. Real person; astronaut; major villain impersonated him J**N *WIGERT
670. Original; anchorwoman; often reports on main character's activities *ANA *EWITT [LOCKED; both remaining letters the same; characters found at time of locking: ABCDEFGIJKLMNPTVWXZ245780]
671. Comics; criminal, orphanage head; All-American Comics; test subject for major villain C*R** G*LD
674. Original; unrevealed; sibling of major villain *RLIN DW*ER'* *I*TER
676. Original; criminal; robbed blood banks for sustenance *ILA* W*ITE
677. Comics; astronomer, assassin; Crisis on Infinite Earths; may have replaced another character with the same code name due to the Arrowverse Crisis DR. LIG*T /  KIMI** ****I
678. Comics; vigilante, prison guard, police detective (latter was cover); Superman; attempted to execute escaped convicts MA*TER JAILER / "CARL DRAPER" [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
681. Comics; newspaper intern turned police detective; Showcase; mistook main character for her husband IRI* WE*T-ALLEN (EART*-2)
683. Original; unrevealed; fan of major character's writing D*RI*
684. Original; some sort of protector (can't be more specific without revealing too much fo the answer); protected cast character DAXAMITE PALACE G*ARD [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
687. Folklore; probably none; folklore of the Americas; fugitive from evil realm C**PACABRA
688. Original; unrevealed; accused of being a witch JANE *AWT**RNE
689. Original; music student graduate; attended University of Cincinnati VANITA RIP**N
690. Comics; princess; Action Comics, though elements of the character from Superman's Pal, Jimmy Olsen; major/cast villain N*XL*G*PTLNZ
691. Original, though possible nod to real person; military lieutenant turned special forces unit leader; attacked government organization for revenge J**NER
694. Original; scientist; created super-soldiers with powers of specific villain METAD*CT*R [LOCKED; both remaining letters the same; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
696. Original; night club owner; main character slept with his fiancée MAX F*LLER
697. Original; executive employee; committed acts of industrial espionage PETE* KANG [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPTVWXZ245780]
701. Original; army member; served under cast character ANT*N*
706. Original; singer; participated in reality TV competition *A*CÉ*
708. Original; football player running back; testified against murderous brother AP*LL* TE*L**
710. Original; scientist; wife of someone who was impersonated for a long time TE** M*RGAN
712. Original; unrevealed; was seen as candidate for human trials DERRICK *IMM*N*
713. Original; director; worked for major studio in 1937 ARN*LD C*LE**N
714. Original; police officer; killed in an ambush J*NE*
716. Comics (indirectly); science based employee to the extent applicable; Action Comics; counterpart of recurring character ALEX DANVER*' FAT*ER (*B*IDIAN PLATIN*M)
717. Original; scientist; ally of main character's mother JET*RIAN IND**T*IE* *EMAT*L*GI*T (note: while not named in the show souce sources claim she's DR. T*VA; I'll accept either name)
718. Original; unrevealed; version of another character, attended a World's Fair EDIT* B*ARDMAN
722. Original; criminal; kidnapped people in a revenge attempt FARZAD *ADIR [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
723. Original; federal agent; killed by cultists DEM**
727. Comics; henchman; Action Comics; member of alien army who confronted another alien for making himself known to a government agency G*R [LOCKED; characters found at time of locking: ABCDEFGIJKLMNPRTVWXZ2345780]
728. Original; mobster, mechanic, repair shop owner; used as source of information by main character ALEXI LE*N*V [LOCKED; both remaining letters the same; characters found at time of locking: ABCDEFGIJKLMNPTVWXZ245780]
729. Similar to comics character with different code name and real name; doctor turned criminal; Wonder Woman;  augmented herself using stolen technology  C*BER-W*MAN /  LA*RA  WA**INGT*N

 

414. Bear

436. Tormock

446. Dana Ford

452. Fuerza/Alexa Rivera

479. Chet Miner

499. Zari Tarazi (robot)

539. Olga

574. Abraham