Fang vs Flik (Suikos): Fang goes Sentinel to survive Flik's opening shot, then slams him with a bunch of status.
Fang vs Tony (MK): Tony's apparently vulnerable to Seal, which in this case I'd use as his check against Pain and Fog. That's that.
Fang vs Cloud (FF7): Deprotect for limit smashing, since Cloud probably immunes Pain!
Fang vs Rufus (VP2): Pain. Even if Rufus goes first she can survive a status blitz with Sentinel.
Fang vs Freyjadour (S5): Goes first. Pain/Fog/outslug/whatever.
Fang vs Garai (CC): Open as Sentinel, Slow/Deprotect, back to Sentinel, then smash to death on a double.
Fang vs Red (Saga): Red's just a bit faster and more damaging than Garai. It makes the difference.
Fang vs Suicune (PKMN): Suicune's great against Heavies who lack tricks, pretty bad aaginst those who have them. The FF13 PCs... have tricks.
Fang vs Auron (FFX): Auron can open with Power Break to try to just survive, but after Slow/Deshell even Ruin spam can probably deal with him. Magic Break helps but probably not enough.
Fang vs Fujin (FF8): Slow vulnerability means that her only real hope (confuse lock) is out.
Fang vs Sync (TotA): Debuffs Sync while he's still harmless, then smashes.
Fang 10-1. Well, there's a reason she gets Goldike hype, even if I don't agree with it. Extremely versatile.
Vanille vs Flik (Suikos): Probably just OHKOs. I suppose I could allow her initial Sentinel as well, but bleh, not something I'm happy with being a cast-wide thing there.
Vanille vs Tony (MK): Gets down Pain/Fog and heals if needed.
Vanille vs Cloud (FF7): Heal, chip, Deshell/smash.
Vanille vs Rufus (VP2): Status quickdraw and I have no idea who goes first.
Vanille vs Freyjadour (S5): Only real question is how she can deal with two straight Crimson Skies. The answer is probably by landing Slow first and then healing. EDIT: No slow. Healing won't quiiite let Vanille survive two skies, so she needs status. And... Freyja can reduce Fog to turn 2, at which point he can finish with a physical.
Vanille vs Garai (CC): EDIT: no slow. Garai's faster.
Vanille vs Red (Saga): Slows and heals, with a death blocker? Nah, Red can heal-lock with DeadEnd, and he'll always have some sort of chance to land it.
Vanille vs Suicune (PKMN)
Vanille vs Auron (FFX): I think Esuna spoiling everything Auron does is pretty bad news for him. His only hope is Shooting Star, doubt that's happening.
Vanille vs Fujin (FF8): Don't think Vanille can learn turn 1 slow against the resistance, barely.
Vanille vs Sync (TotA): See Fang. EDIT: No slow, but she can still stall against pre-MA Sync all day and then summon past the scary stuff.
5-5. Fang minus, basically. The healing does help, but no Slow hurts a ton.
Snow has 125% HP, but while in Sentinel (which he mostly is), he's effectively (HP included) multiplying all damage by 0.45. He can use Mediguard which is a two-turn action as far as I'm concerned, but the extra turn it grants his enemies is instead multiplied by 0.16.
Snow vs Flik (Suikos): Flik's two L4s take out most of Snow's HP even if he stalls, and the L3s are good enough to finish things from there. Close though.
Snow vs Tony (MK): Spammable 2HKO tends to beat Snow. The break just adds insult to injury.
Snow vs Cloud (FF7): Chip Cloud a bit to weaken his offence, then stall against him until summon.
Snow vs Rufus (VP2): Rufus' raw spammable offence is too good, never mind the status.
Snow vs Freyjadour (S5): Hm, think Freyjadour's physical offence is just good enough to get around Mediguard, he's surprisingly solid at it.
Snow vs Garai (CC): Spammable 2HKO.
Snow vs Red (Saga): Spammable 2HKO. Well, runs out eventually, but not fast enough to lose since it's a good 2HKO.
Snow vs Suicune (PKMN): FRLG form wins this with Calm Mind, but Rain Dance doesn't give the punch needed when Suicune only has five shots of his good damage. I guess he could go for a flinch chain but I doubt that's working.
Snow vs Auron (FFX): Auron goes first and uses Power Break, so Snow needs like 6 attacks to kill him. Magic Break ensures that any such attacks trigger counters. Zombie Attack comes last to rule out any stalling.
Snow vs Fujin (FF8): Status.
Snow vs Sync (TotA): Snow might actually survive a Mystic Arte! Barely. If he were at full HP when it hits, which it won't be. EDIT: Stall until summon works, though. Haha Sync offence at full HP.
Snow is a bit better than I thought in that him being in Heavy actually isn't a joke. But still probably doesn't belong there, odd spoiler. 3-8