I am pretty much stumped right now...
I had 45% resist + 1 lifesteal + a few DR from EM:
https://imgur.com/a/kKFikNE
Went through all other bosses without any problems, but cant seem to get him down through the enrage phase
Here is my end screen for the strategy:
https://imgur.com/a/WDVSaW5
To EB Warmonger Curious: Now you are just showing off I dont think, the devs ever intended that to be possible