Godlike
Izanami (Persona 4) vs Ameno-Sagiri (Persona 4) - Sure.
Shania (Shadow Hearts: From the New World) vs Culex (Super Mario RPG: Legend of the Seven Stars) - Culex can take turns to summon his Crystals back in, but they aren't part of him, so I'm not letting him start with them out. Combined with my harsher view against optional bosses, and this is far more weighted towards Shania.
Heavy
Lashiec (Phantasy Star IV: End of the Millenium) vs Lenus (Legend of Dragoon) - Man, Meru just wishes she could make this much use of the Blue Dragoon Spirit.
Nel Zelpher (Star Ocean: Till the End of Time) vs Vyse (Skies of Arcadia) - I'm still not entirely sure, but coinflipped towards Vyse.
Middle
Ray (Fire Emblem: The Sealed Sword) vs Natalia Luzu Kimlasca-Lanvaldear (Tales of the Abyss) - Taunt or Revive your way to Overlimit. Plenty of ways to avoid impaling herself on Ray's weapons.
Light
Raticate (Pokémon) vs Viki (Suikoden Series) - S4 Viki
Mallow (Super Mario RPG: Legend of the Seven Stars) vs Vitali (Soul Nomad & The World Eaters) - Two of my favorite lights, damn. I'm pretty sure Mallow can run Vitali out of resources. It's times like these that Vitali wishes he has a damage-dealing Limit.