Ive testing this in several towns, CC and Gadz, and it seems to be a cool glitch/exploit. Pretty much summon an infernal onto a group of the opposite factions. It will attack and kill any of those memebers but not put you in combat, as long as you don't tell it to attack anyone. But all those it lands on will be put onto its aggro, so it will attack all those w/o u telling it to. This also doesnt put you in combat.