"Alive" essence

Twice before, I found an "alive" essence. Before releasing these essences, they were particularly invincible keeping all their assumed to be buffs. One time, they were inflicting damage, while running around (chasing me) while still unreleased.
I have the bug report number, from the last time it happened; and screenshots if they are needed.

I just got this now.
In my case, they were enemies from an added conqueror influence allflame. So when the essence encounter was scrolled on screen, their spawn animation played and they immediately began attacking, though they were unable to walk around.