[Autumn]

A simple version of this is to inflict people with a permanent duration knockdown on the next round whenever their HP hits 0.

Knockdown goes away only when it uses up your Momentum, and when you're dead you don't use Momentum, so it won't cause anything wrong, on paper.

if you were to activate die hard or be revived during knockdown you'd spend momentum getting up after being revived, essentially making you miss a turn due to the momentum deficit of already being KO