It's not really that impressive, to be honest. I was seeing about 850 a hit, about 40 hits per overwhelm, for 34000 damage. That's two Piercer + followups, and those Piercers work as emergency party dodges (for when Gladio goes to kiss a malboro right before Bad Breath, for instance).
I mean, yes, it's great damage considering it's a single technique. Strongest single attack? Sure. OP? No. 3400 damage per second is actually pretty mediocre, and there's a lot of ways to achieve it without wasting the tech bar.
ethan3210: I have a ton of RPG's, but what's so special about this one?
Strain42: The blank faced standard anime-esque RPG protagonist wears a hat.