"Is this ability too strong?"
makin' shit for valiant horizon, where the powers are one use per fight. So, by nature, they're to be fuckin' strong.
then i go and look at a final fantasty tactics speedrun and watching fights just get rolled after 2 spellcasts.
or thinking of my own experiences in like Lancer where one good turn resulted in say, single handedly half-healthing an Ultra.
I think like, playing Armored Core 6 NG+ completely solidified and firmed up my belief that EVERYTHING should be strong and """busted"""
Because it lowers the floor for passable play.
I can run goof-ass builds in AC6 because everything's strong.
Unless I deliberately go like, the smallest frame, the smallest weapons, don't load up my weight to its limit, I can just clown through.
And even then, if that gigalightweight build includes a sword its over because its a sword.
And peeps who don't want to do that can always go down ol' reliable double zimmy/songbird.
Back on this in regards to a tactics TTRPG, something to also consider is the massively uneven tactics-savyness throughout a party.
One person might be there to vibe with friends.
One person might be there for the story.
One person might be there just to roll dice.
One person might be there to create a fuckin' monster.
And combat is designed to be won. TPK is a failstate, and only recently has there been big, hard-mechanically written strides to mitigate that endstate.
There's also a bunch of tech one could use to further mitigate a TPK, pull some Doom 16 tech and make being lower be worth more [Valiant Horizon does it via Determination, lets you survive at 1 HP].
all this to say its cool when players are strong because then the GM gets to play with strong enemies and it's fun to be strong.