Reicher (Mana Khemia 2: Fall of Alchemy) vs Airy (Bravely Default) - EDIT: by my scaling (Reicher has roughly 1.8x raw PC HP not counting his Chaos Shield clone, reduces mag damage by 42%), Airy actually misses the 2HKO even before Reicher's shield if she doesn't cast Acedia. This... is actually too much time, letting Reicher get two full turns alone lets him pump over 3x PC HP, let alone THREE. I don't think her Default => Brave string saves her either - HERE, his shield lets him avoid a 2HKO, which means Airy effectively wastes a turn by trying Acedia shenanigans. Airy's not quite ridiculous enough to survive to her third turn (she's about 3.4x PC HP to me), methinks, but that's a good fight.
Amon (Lufia 2: Rise of the Sinistrals) vs Jowy Atreides (Suikoden II) - I guess I can buy Jowy being faster. Lufia 2 endgame speed is a slightly more nebulous matter than simple DL-legal comparisons and it doesn't really favor the enemies.
Izlude Tingel (Final Fantasy Tactics) vs Chrom (Fire Emblem: Awakening) - I think this is actually a similar matter to Karsh vs. Izlude? Izlude does thank his stars he can avoid Chrom's counters, at least.
Tia (Lufia 2: Rise of the Sinistrals) vs Andre (Shadow Hearts: Covenant) - i guess
Upgrade/Downgrade Pools
Isolde, Jowy, Amon, Beowulf, Luca, Red Fiend
As before, abstaining on Red Fiend due to non-existant memory. This said, this is pretty straight-forward. Isolde > Jowy > Luca > Amon > Beowulf, all things said. Just different slugging levels at play. Isolde rips all the losers' skin to shreds, not much to see here. Jowy actually has quite a good showing: he owns Luca the same way he does Amon, i.e. faster 2HKO, and I'm very much not willing to give Beo's highly stat-check-reliant status a free pass against Jowy, who has a lot of the right stats here. Luca should be able to 2HKO Amon himself without eating a 2HKO, which is good, since he goes last. This said, Beo's Drain isn't really good enough to outpace either Amon's or Luca's offense due to its gravity-based effectiveness and imperfect accuracy, and he's sacrificing either HP or evade in order to wall the flame slashes in Luca's case (if he does neither, things get worse). Beo's just not really great against bosses.
Isolde: 4-0
Jowy: 3-1
Luca: 2-2
Amon: 1-3
Beowulf: 0-4
Hiro, Elly, Izlude, Chrom, Hrist, Vyse
Okay, let's do this. Hiro mulches Elly, Izlude and Chrom. I'm not sure -where- I peg his damage, but it should be -at least- above average, which should let him beat Izlude (Poe Sword is ranged and avoids counters, being comparable damage to his physical chain post-crit factoring). Elly and Chrom eat it to Dark Sword. Hrist... well, this one's more complicated. He may not 2HKO her, but she also may not 2HKO him back if she's blocking instant death... though petrify. Hiro comes with a blocker for that, then. I suppose the average of assumptions favor him there, he might still win if he doesn't block stone and she -dies- if she comes without ID protection. So, he sweeps. Elly... well, first I need to check if Chrom doubles her. If so, oh dear, that's not pretty. I'll get back to you on the rest of this pool.
Maya, Frog, Tharja, Ranger
see above