Immortal reviving partially invisible Azzmeri spirit

Hey! I assume what just killed me must have been a bug since I have never encountered this before. And it was rather absurd..

I was on the map Wetlands where i encountered an Azmeri spirit - nothing unusual about that. It possessed one of those snake-zombie guys (the ones you first encounter in the jungle in Act 3). I proceeded to kill Mr. Snakeman, who dropped some loot but proptly revived again - and now possesed by 2 Azmeri spirits. I kill him once again - repeat.
This time, after revival, he decides to be invisible for some time. I kill him - same thing happens.
He is now possesed by 4-5 Azmeri spirits at the same time - and he turns invisible. I die. Luckly - my T15 Waystone allowed for one retry. I try again and manage to kill him - aaaand he revives once more and kill me when invisible.



-No spirit omens active in inventory by the way.

This must be a bug, right?