What are the most dangerous unit combinations in Dungeon?

I experimented with builds for maximizing mirror images in the late game (focusing on artifacts that boost initiative + attack + Unicorn Bow or a runic set to increase chain damage).
Basically, the hero casts "Stopping Cold" and the Erin specialization ability = tons of damage from the Sovereigns. The most interesting thing is that the debuff remains on the target after the Sovereigns' attack, which allows you to use it again with the next attack from another creature.
A screenshot is attached.