Answered Singer Barb with Atma's Scarab

Warcry doesn't proc atma's. The best solution is to just teleport past immunes with enigma or a teleport staff--they aren't really worth your time to kill

But if you want or need to kill them, then lawbringer or reapers toll on a merc are good options, and you self-wield insight. This is also a good way to boost your damage vs monsters in the endgame. The third repair-heavy route is putting spellsteel or gavel of pain on swap