Eruca (Radiant Historia) vs Hero (Dragon Quest V: Hand of the Heavenly Bride): Snowfire. You do realize that against one-hit enemies Eruca can just use Divine Light and get as much of a ten-turn chain, right?
Uh... that's... okay, sure, vote changed. There's basically never any reason to switch a turn far in the future in-game which is why I was assuming by default that it's only worth getting a double-turn for (or triple turn off a natural double turn), but Divine Light spam can set that up so long as Eruca is faster. And I think she still only gets a triple turn off this, not anything crazier (if that was ever needed)? Look at it this way:
Eruca1: Divine Light
Hero1: Hit
Eruca2: Switch with Hero3 turn
Hero3: Hit
Hero2: Hit (Eruca in massive pain)
Eruca3, Eruca4, Eruca2: Damage -> Win.
(EDIT: mixed up Hero4/Hero3 somehow before)
Seems like it should be that when Eruca uses the Divine Light strategy:
Faster and 2HKOs / Slower and OHKOs: Eruca gets one turn at a time safely. (Can still win, but not vs. Hero who has Fullheal and great MP reserves.)
F & 3HKO / S & 2HKO: Eruca can set up a triple turn using the above strategy.
F & NHKO / S & (N-1)HKO: Eruca can set up N+1 turns in a row.
Where faster and slower are strictly init-related and ignoring natural doubleturns.
Re the enemies in the sewers: They did indeed use an attack called "Death shot." I never saw it connect, though. But it did terrible damage so I assume there was some status hype behind it, rather than being an attack with naming aspirations larger than its abilities.