Warlocks who spend most of their talent trees in the Demo tree deal a lot of their damage with their companion, usually the Fel Guard. This pet does not only gain power from several talents in the tree but also scales with the Warlock's equipment and stats like stamina, intellect and especially spellpower. At the same time the Fel Guard has the ability of buffing the whole raid or group whenever he scores a critical melee hit. This buff increases everyones spellpower by 10% of the Warlock's spellpower. Unlike most other buffs this is a unique buff and can not be brought by another class or spec.

The Warlock himself will use the usual DoT spells like Corruption and Curse of Agony, casting Shadowbolt between refreshes. At the same time he will send his Fel Guard to melee the current target. Unfortunately there are some fights that are rather melee unfriendly, so the Fel Guard is at a disadvantage there. Eventually the Warlock will have to take care of his pet or switch to the Imp, as that is a ranged pet and can stay in the safe zone with the Warlock, increasing its survival chances.

The ultimate talent in the Demonology tree allows the Warlock to transform himself into a powerful demon, at least for 30 seconds. This Metamorphosis increases the Warlock's damage by 20% and he has access to several special demonic abilities that can deal substantial damage in close combat. To increase the survival rate in melee combat the Warlock's armor is increased by 600% while in demon form.