Dimitri vs. Luther (Star Ocean 3): I don't think Dimitri winning this is totally crazy... but probably not. Luther lands something accurate to lower tha evade, then does horrible things, and I have a lot of respect for his speed.
Dimitri vs. Terra (FF6): Dimitri's turn 1 evade is just over 50% even using magic, I believe... but if that goes his away we can assume many other things won't. If Terra hits with her first Drain then Dimitri's in loads of trouble, if she misses then Dimitri can just try to 2RKO. Dimitri needs to land 6 out of 8 hits to do that, and that's... kinda dicey.
Dimitri vs. Monk (Bravely Default): Faster, 2RKOs. Monk needs to hit all four shots of Qigong Wave to kill Dimitri and that ain't happenin'.
Dimitri vs. Raquel (WA4): Raquel's parry and counter bullshit is probably really annoying for Dimitri, but then she has trouble hitting him too... oh wait, Swordbreaker. Yeah you don't want to use swords against Dimitri.
Dimitri vs. Scias (BoF4): Yeah you don't want to use swords against Dimitri.
Dimitri vs. Lenus (LoD): Dimitri can... probably 3RKO while only triggering the limit turn 2, and Lenus' opening Boomerang will probably miss. But Lenus' limit will probably hit 2/2 (especially since it's magic) and that kills Dimitri.
Dimitri vs. Red (Saga Frontier): Ranged ITE is what you want, here.
Dimitri vs. Justin (Grandia): More foolish sword-users.
Dimitri vs. Ephraim (Fire Emblem 8): Dimitri doubles here, which more than offsets Ephraim's superior base damage. They have similar pdur and evasion overall, so I think the doubling makes the difference.
Dimitri vs. Princess Toadstool (SMRPG): I'm pretty sure I use charm as the defensive stat for status in this game (Silence doesn't check it, but IIRC enemies never use that, so the main status to defend is Rattle). Which probably saves Dimitri here, since Toadstool's best strategy is repeatedly sleep->heal->attack (if you see that not triggering counters), but one miss and she's dead.
Claude vs. Luther (Star Ocean 3): Again, just too much respect for Luther's limit-mode speed here. He doubles nearly constantly to me, which crimps even a well-timed Fallen Star.
Claude vs. Terra (FF6): Claude can barely 2RKO with Fallen Star -> Brave Bow x4... except one hit is gonna miss, so nope, Terra gets two turns, and one won't be evaded. The turn Fallen Star IS active, she'll use for Cure 2, so honestly that's kinda wasted. Never mind Fallen Star then, Claude just goes for 2RKOing. Terra... actually by the old topic she OHKOs with Fire 3, might miss with Dhyer's which uses higher MDef, but still Drain + Fire 3 works and his magic evade is likely to go 0/2.
Claude vs. Monk (Bravely Default): Fallen Star -> kill works here. If Fallen Star totally spoils one brave-chain then this is a joke, but even if it only gets one, Claude is likely to evade at least one time in four and Qigong only 3HKOs.
Claude vs. Raquel (WA4): Fallen Star/Encloser spam? Very dicy since Raquel has hella evade and Moonlight ensures that letting Encloser slip once is bad. If going for direct offence, Claude needs 8 Brave Bow hits (he quads) and a Fallen Star. The Brave Bow offence needs about five turns of trying... maybe less with counters though? Raquel 2HKOs with some reliability once she's not being locked down. Neither strategy seems to work for Claude.
Claude vs. Scias (BoF4): More traditional Claude style of win. Alert Stance lets him essentially strike first (even if threat range doesn't), and he can 2HKO while nothing Scias can do in one turn is decisive (sleep misses due to charm, damage doesn't OHKO, healing is a lock).
Claude vs. Lenus (LoD): Even carefully chipping, Claude can't just Fallen Star -> Brave Bow through the limit range. He can Brave Bow twice but then the turn in the middle leaves him very dead.
Claude vs. Red (Saga Frontier): Does Fallen Star work on ITE? It doesn't matter here because Fallen Star + Brave Bow doesn't 2RKO anyway.
Claude vs. Justin (Grandia): Hold a grudge if you must.
Claude vs. Ephraim (Fire Emblem 8): Encloser is probably aces here. Strategy in motion.
Claude vs. Princess Toadstool (SMRPG): See Dimitri's match.
Ceodore vs. Luther (Star Ocean 3): Yeah no.
Ceodore vs. Terra (FF6): Drain going through Reflect mostly ruins Ceodore's plans. Still, she doesn't have a good way of putting him away, between Blink and his elemental resistance. This fight will only end when one of them runs out of MP... ugh. Let's go into detail.
Ceodore shouldn't cast Haste, because Dispel costs the same MP and Terra has a higher raw total. Unless he casts Reflect, but that's shaky too. Their healing have comparable number of uses. Terra 3HKOs with physicals... but that needs Morph, which will run out in a long fight. So 4HKO with unmorphed physical x3 + Morph to finish. Ceodore needs to switch to a non-elemental weapon and thus 5HKOs himself, while facing evade. He can use Blink to ward off two physicals instead of healing to ward off three, which saves MP but wastes turns... too many, for sure. Terra needing to use MP less often is decisive, as these types of fights often are; Ceodore's slight speed advantage helps but isn't enough.
Ceodore vs. Monk (Bravely Default): Blink wards off a ORKO from Monk, at least short term. Monk can't just punch once because Ceodore is faster and has the MP to spam Blink until he doubles. So instead Monk tries to get 2 BP so he can Qigong x7 over two turns, which Ceodore has no answer to. Ceodore gets three extra turns before that happens after his opening Blink. Does he 3HKO? Looks like he does.
Ceodore vs. Raquel (WA4): Raquel sure hates Blink, although she can Moonlight three times then Intrude past it. That's a lot of turns to give Ceodore, but unlike Monk he doesn't have a quick kill in the meantime. Ceodore gets five turns after his opening Blink, but he can't kill in five or even close (i.e. I don't think Haste helps either).
Ceodore vs. Scias (BoF4): Scias is... fractionally faster to me, but Ceodore's ice resist means he only 3HKOs. Ceodore also 3HKOs. I think Scias wants to use Sleep here... in fact against the slower, Sleep->Disembowel->kill seems safe... unless Ceodore is hasted, which will stop that strategy. So yeah, I think opening Haste puts this out of reach for Scias. Ceodore can spam Blink to prevent a cheesy Rakshasa death, as well.
Ceodore vs. Lenus (LoD): Setting up Haste/Reflect seems good? MT spells go through Reflect, though. Double Black Rain will hurt, but not kill. So the strategy is to Haste/Blink, chip Lenus to just above 60%, add on Reflect, use Awakening, then smash through. Should work.
Ceodore vs. Red (Saga Frontier): There's a case for Re-Al ignoring Blink but I'm not inclined to buy it.
Ceodore vs. Justin (Grandia): More Blink hype.
Ceodore vs. Ephraim (Fire Emblem 8): And again.
Ceodore vs. Princess Toadstool (SMRPG): Don't think Toadstool has a way to tilt the fight her way, while Ceodore of course does.
Celes vs. Luther (Star Ocean 3)
Celes vs. Terra (FF6): Celes is fater and has status options. Terra's only hope is to use White Cape + Peace Ring to make this a status-free fight, but Haste/Safe still tilt things pretty far to Celes' side. Just... Drain's a big problem. In fact an insurmountable one. Funny, I always used to vote the other way back when "only one statusblocker" was a thing.
Celes vs. Monk (Bravely Default): lol
Celes vs. Raquel (WA4): Imp time.
Celes vs. Scias (BoF4): Even if Scias is seen as slowing all the status, he can't stop it, and he needs to.
Celes vs. Lenus (LoD): I'm inclined to see the Minerva as halving dark (if you don't, Lenus has this for sure), but yikes, Dark Mist x2 is still brutal and Celes has no quick ways to end this. Lenus 2RKOs so even with Haste Celes is heal-locked.
Celes vs. Red (Saga Frontier): Safe reduces Red to a 3HKO, but Cure 1 isn't patching that up long-term. This would be one of those fights she wants Vanish for.
Celes vs. Justin (Grandia): Better status-slinger.
Celes vs. Ephraim (Fire Emblem 8): And again.
Celes vs. Princess Toadstool (SMRPG): Muddle or Berserk + Safe (Toadstool's physical doesn't put on the pressure of Re-Al).
Ceodore 7-3
Celes 6-4
Dimitri 6-4
Claude 5-5
They're similar! Despite the fact that Ceodore did the best I actually kneejerk him the worst dueller here; I feel like he got some good matchups... but I might also be underrating him. You don't expect someone with a 3HKO, no status, and decent but no especially stellar stats to be borderline Godlike.
Among the opponents, Luther and Terra are Godlike, with Raquel/Lenus/Red putting up the next best showings, they're probably all near the border themselves. The rest all belong in Heavy.