How do I kill this thing? Lvl 72 Arc Sorc and barely putting in a dent before he regens back up

He has azmeri spirit which gives a lot of life, and he’s regenerating faster than u can burst him down. It’s a dps check

What’s your lightning pen? He looks resistant

No catch, you just need more damage!

Was there a black cloud floating around near the monster? You can't damage them unless your own character is inside the cloud with him.