Infernal spell originally summoned an infernal for the Warlock to enslave after the 5min enslave fades. Most likely the warlock just let it loose instead of enslaving it again. In any event, looks fun, kinda like the ritual of doom roulette I would always subject lowbies to in Goldshire then let the Doom Guard run rampant.
Inferno spell
http://db.vanillagaming.org/?spell=1122Ritual of Doom (for those locks that want to wreak havoc in low areas xD)
http://db.vanillagaming.org/?spell=18540