Godlike
Myria (Breath of Fire Series) vs Heat (Digital Devil Saga)
Virginia Maxwell (Meeple Fantasy 6) vs Lady (Shadow Hearts: From the New World) - Virginia equips Gale Claw for the speed boost, Cosmic Cog for the defense boost (and ANOTHER speed boost?!) to buy the first turn. Buffs her Mdef with Shield to tank the initial Double Stock barrage from Umbral. Depending on how well that goes, Ginny can opt to remain at lowish health to boost her physical (dangerous, and not sure how much low health increases her damage output), or she can heal fully with Mystic. After that inital Double stock burst, Ginny should have the speed and resources to keep ahead of Lady and Unbral's ridiculous turns. She can bust their speed if necessary. She definitely can't rely on her physical for the final blow however, because Lady's Malice Dirge would destroy Ginny if she's not at least close to full health. I think it's close, and Ginny has to heal a lot, but I don't see any of Unbral's or Lady's attacks as 2HKOing.
Ryu (Breath of Fire III) vs Yuri Lowell (Tales of Vesperia) - think he just one-rounds him.
Tir McDohl (Suikoden Series) vs Arceus (Pokémon) - I guess dark defense?
Heavy
Nope.
Middle
Yukiko Amagi (Persona 4) vs Iris Fortner (Atelier Iris 3: Grand Fantasm) - Go Iris! I dunno P4 yet.
Danette (Soul Nomad & The World Eaters) vs Leonardo (Fire Emblem: Radiant Dawn) - Danette's fast enough to go first, that might be good enough.
Naoto Shirogane (Persona 4) vs Flay Gunnar (Mana Khemia: Alchemists of Al-Revis) - Gah, I want to play these new games.
Light
Vitali (Soul Nomad & The World Eaters) vs Laura (Fire Emblem: Radiant Dawn) - ridiculous free healing. She'll eventually run out of weapon charges...
Labyrinthia Wordsworth (Wild ARMs XF) vs Isadora (Fire Emblem: The Blazing Sword) - haven't played it, but it looks like she wins from the stat topic.
Colette Brunel (Tales of Symphonia) vs Ilyana (Fire Emblem Series) - spoiled?
Keele Ziebel (Tales of Eternia) vs Lulu (Suikoden III) - fail-off. Keele has some interps where he doesn't entirely fail, that's good enough.
-Djinn