Yukiko vs
EB Poo - *PSYDUCK*. Okay, this is vaguely failure. Poo's best damage here is actually PSI Freeze Gamma (Stat topic doesn't list this since Starstorm Beta > it normally) due to Yukiko's Ice Weakness. He's not bothering with status because if he does, Yukiko equips that fan that blocks confusion by 50% and mocks the status odds EVEN FURTHER. There's no damage figures from the stat topic for Freeze Gamma, so I ran through the Starmen.net database to pick up the damage, which listed on average 540. I'm basing the rest of this calculation from that. FYI, Freeze Gamma's PP cost is 18.
540 ice damage after Yukiko's ice weakness becomes 810. EB stat average for damage is 720? But the damage largely doesn't matter due to press turn. I don't think she had anyway to null this weakness from armors. So, assuming that the Miori Shirt evade is her armor option (and I honestly don't know if she wants another one here), she basically needs to kill in exactly three turns before Poo stun/dizzy locks her to death. One shot of Agidyne (based on the damage average that includes Souji's HT), is something like 0.89 PCHP. Poo is roughly average durability, is faster and has enough PP to fullheal 3 turns. Okay, so that won't work.
Which means! Her best option here is to actually try and status him with Exhaustion (...). This normally doesn't matter, but the SP drain is notable since Poo has resources of failure. Thanks to the Sukakaja, her accuracy is boosted, so Poo's chances of evading will be slim to 0. The hit rate on exhaustion is 30% per stat topic. Do I see this by turn 3? *thinks*
...If it was like a couple points higher I could see it (like 33 and above). YMMV. But yeah, not today. Poo's healing PP cost for 3 rounds + 4 shots of Freeze Gamma is 111. He has 140 SP. So yes, he can kill before running out of PP. Note that if Exhaustion hits he is up shit creek without a paddle though.
*EDIT:* Okay. So this fight just got even MORE psyducky. Thanks EB mechanics:
http://starmen.net/mother2/ebdb/psi.php?psi=10.
I am going to ASSUME therefore, that Snow's stated figure of 60% what EB states is correct for Freeze Gamma average. If you decide to take Freeze Gamma damage at 540 or something, be my guest >_>. This drops Poo to 324 damage before weakness hitting, which bumps him back up to 485. NOW THEN...
Since Yukiko deals only 0.89 average as mentioned earlier, Poo only needs to heal once on turn 2 - basically Poo does something, Yukiko hits him with Agidyne, Poo does something again, Yukiko uses Agidyne, Poo heals. He saves 13 PP this way, which means more Freeze Gammas. After one Healing gamma, Poo is down to 127 PP. He can use 15 Freeze Gammas and possibly a Freeze alpha or something afterwards. 15 Freeze Gammas at 485 damage a piece is 7275 EB damage, definitely enough for a kill. Yukiko only has 89% average for HP (roughly 2.14 or something), so yeah. Poo still kills via Dizzy locking.
If you see Exhaustion hitting Poo, this strategy fails though because of the PP drain, meaning he probably can't get out the needed damage before running out of PP. Then Yukiko just fries him.
*EDIT 2*: Did some more thinking. Assuming that Yukiko will recover after getting dizzied once (ie: Once dizzied, guaranteed to recover after one turn is skipped) since I think *that's* how Dizzy actually works in P4, Poo's best option becomes Freeze Gamma*2 to induce Dizzy and then 2 shots of Starstorm Beta at 720 damage a piece. Thus, actual damage is 458*2 + 720*2 or 2356. Total SP cost is then 133 (13 spent on healing. 42 for Starstorms) Kill point using 2.5 average in EB is 1800 or so. Yukiko's durability from raw HP is 0.89, made worse by the Miori shirt probably. Yeah, definitely leaning Poo if you don't see Exhaustion kicking in.
Yukiko vs CC Grobyc - Yay, something less complex. Anyways, evade makes this simple. Grobyc needs to like hit her with a full chain + a L5 tech+ in order to kill or something. Miori's Shirt evade should definitely kick in somewhere and screw that up.
Yukiko vs
WA Rudy Roughknight - Can only vote on ACF Rudy here, which is enough. Snipe Bullet's + Hit means Miori Shirt evade hype is a no go from me. And yeah, Yukiko's not 3-2ing so Rudy will have a chance with Lock On + something (probably Claymore) to finish the job.
Yukiko vs
MK Flay Gunnar - Buster Star does horrible horrible things here. Flay's durable to boot
Yukiko vs WA2 Brad Evans - I have no clue off hand. Strongly leaning Yukiko because Brad needs to OHKO as anything else gets healed off by Diarahan eventually. Having played what I have of WA2, he basically needs Boosted Rail Gun in order to do this (correct me if I'm wrong), which means he needs to get 100 FP. Feels like he is just wasting too much time.
Yukiko vs G2 Ryudo - Ryudo needs to OHKO or something because he is running into even WORSE resource issues than Poo (...) if he just heal locks. He's best off trying to silence Yukiko with the godly status hit rate sword of 10% or something before it runs int Miori Shit evade. Um...something tells me this isn't going to work.
Yukiko vs CC Leah - More evade! Boy do CC fighters absolutely hate this. Guess they can try to use just L1 physicals all the way through to build up the gauge, but don't see it killing in time. Plus they needa full chain on the killing turn, and that runs into evade.
Yukiko vs
XS Jr. - Misty makes this easy.
Yukiko vs FE8 Lyon - Not exactly sure how Yukiko is avoiding counters (she still triggers although them missing I would buy). Not sure that matters either because Lyon's AS from memory is something horrible. Which means he is likely getting double. And even if not, he still has to go through endure and has FE8 boss HP to deal with.
Yukiko vs
FE9 Mia - Um...hm. My gut is to say that Mia gets through the evade (swords + Swordmaster hit), which is really bad for Yukiko. Stalling's out unless she really wants to get crit in the face. I don't even know if Mia doubles, but if she does, this gets even uglier.
Yukiko vs G3 Ulf - Gee, if Snow doesn't see Ulf having a chance here...
Yukiko vs PKMN Moltres - Voting on Gen 3 here. Using hinode's note as his best damage, following is what I think happens: Yukiko (Fire break) -> Moltres (Leer) -> Yukiko (Agidyne) -> Moltres (charge SA) -> Yukiko (Agidyne) -> Moltres (SA goes off) -> repeat until one of them dies. Given how Moltres' first SA has like 50% accuracy (90% base before factoring in Miori's Shirt's evade), I really don't think he wins. Even if he OHKOs since he basically needs to do it twice and it requires a turn to charge. Someone can prove me wrong though.
Yukiko vs
PKMN Blaziken - I'll buy Bulk Up + Sky Uppercut OHKO here.
Yukiko vs
FE7 Canas - Nosferatu + counters makes Yukiko very emo
Yukiko vs CC Karsh - More of that evade jazz
Yukiko vs FFT Vormav Tingel - See Snow basically
Yukiko vs
FFT Ramza Beoulve - Aegis Shield + White Robe I think. Halving Fire means Yukiko probably needs to Fire Break. Aegis just makes things worse in terms of hitting (although your respect may vary). This means Ramza has time to actually set things up. *EDIT: Wait Ice Brand. Stun lock after turn 3 with above defense set up go go go*
Yukiko vs
FE8 Valter - Oh Valter doubles? Welp.
Yukiko vs FFT Wiegraf Folles - Riovannes Wiegraf HP is so awesome. After Endure, Weigraf basically 3HKOs. Not good enough. Note, Monastery Wiegraf might actually be better here (think he had White Robe + Elf Mantle), but yeah don't vote on that form myself.