Girgashiy in Decisive Battle

I can Confirm this too as I just Exited from the Shadow Mission.

I barely got to 20% before it started using soul absorption and I exited as im not planning to scream again. My pets keep dying before I can use them to resurrect myself, but I found out(not sure if its a glitch)that running with a horse seemed to not let either the mining hail or the poison affect me....although, once I got close, it started affecting me but from a distance, it seems most attacks are dodgeable while riding a pet but I cant really confirm if its possible for others or me just being a bit laggy cause it.