When Eden's Gate came out, I got my very first E3S kill thanks to the very very very long wind-up animation before the damage happens.
I'd prefer it that players are warned of "enrages" as late as possible, since people throwing themselves off prematurely when the bosses are at sub 1% is kind of troublesome. (Unless it's a case of the boss going invuln, then sure... swan dive away)

Have no feelings about the add-phase kind of enrages though, they're kinda just there