I think he's referring to Zentetsuken, but that's the only truly instant death move I can think of. Maybe one of the other bosses has a doom ability. It's there, it's just not used (in my opinion) excessively.
Remember: the question here is: "Do you think instant death is overused in this game, and/or do you think it is a necessary/effective difficulty mechanic?
and I"m not talking about high damage AoE, I'm talking about stuff that's basically guaranteed to oneshot everyone (or everyone except the tank with 3x the HP of everyone else, which may as well be everyone since the tank will subsequently die)
