Godlike
Lenus (Legend of Dragoon) vs Yaridovich (Super Mario RPG: Legend of the Seven Stars): Yaridovich is faster and 3HKOs with physicals (I take them at 2/3 potential damage, YMMV... if anything there's an argument for that to be higher against bosses, lower against people with evade). Lenus still outputs damage like crazy (counter then normal turn) and can do nearly 3PCHP in this fight, but Yaridovich magic durability is kinda crazy (1.5PC or so, then cuts magic by nearly two thirds).
Melfice (Grandia II) vs Luther Lansfeld (Star Ocean: Till the End of Time): Sure. Luther will get at most one Perfect Symmetry off, and I think he survives that. edit: But if his parts don't have evade, I feel like I shouldn't give him much credit at evading AoE attacks.
Dr. Nusukan (SaGa Frontier) vs Luca Blight (Suikoden II): Bah, never figured out how I felt about Nusakan. Abstain, since it definitely matters here... with Shield, he can turtle due to relying on evasion and infinite healing (and mocking fire). Without he gets heal-locked.
Orgulla (Xenosaga: Jenseits von Gut und Bose) vs Profound Darkness (Phantasy Star IV: End of the Millenium): Orgulla can probably two-shot PD (10.4x PC damage, yeouch). This needs three setup turns in total, so PD gets four turns. Orgulla can tank four turns of near-PCHP damage well enough, I think, especially when the opening two hits hit her high MDef. Heck, she may tank 5, or get in a doubleturn at some point, either of which would make this an easier win.
Heavy
Asellus (SaGa Frontier) vs Ray (Fire Emblem: The Sealed Sword): Crazy. But I think Snow's right. This is some high-grade spoiling, Asellus barely misses the OHKO and can't do anything to get herself two useful turns.
Lundgren (Fire Emblem: The Blazing Sword) vs Marcello (Dragon Quest VIII: Journey of the Cursed King): Surely.
Justin (Gradia) vs Alakazam (Pokémon): If he survives a hit, he takes this.
Middle
Sara (Breath of Fire) vs Lorelai (Suikoden Series): Easy.
Lich (Final Fantasy) vs Dalton (Chrono Trigger): I'm going to be contrary here and say Lich gets hit by gravity, gravity is generally a hard immunity to get (impossible for CT PCs!) and Lich has all sorts of status holes. Still think Lich 2HKOs the frail Dalton, though, so Dalton gets off one counter and one of his own turns. This lets him win... unless one of the Iron Orbs misses. So do I subject Iron Orb to Lich's status resistance? ... yeah, probably. Dalton only just misses needing one, too bad for him. edit: Nah, changed my mind, the idea of unresistable gravity attacks running into status resistance doesn't really make much sense to me, I can't ever see myself saying Dalton's Iron Orb misses against PS4 psy equips or FE res. So Dalton wins.
Light
Mao (Shadow Hearts: From the New World) vs Mojo (Chrono Cross): Mojo is faster and barely 3HKOs average (surprising). Mao also 3HKOs. Mao is basically average durability... good HP, bad Def. Huh, feels wrong, but the slight speed gap wins this. edit: On the other hand, the more I think about it the more CC speed hype is a suspect thing, and Mojo could very easily fail to 3HKO, since accuracy makes his damage uneven.
Serph (Digital Devil Saga) vs Big Joe (Xenogears): No.
Raijin (Final Fantasy VIII) vs Irvine Kinneas (Final Fantasy VIII): Don't think my Raijin respect is so low as to lose him this.
Kiros Seagill (Final Fantasy VIII) vs Liliane Valendorf (Mana Khemia 2: Fall of Alchemy): Because if she loses to Kiros we damn well need to boot Mana Khemia 2 right now.