Infernal: 15m duration, 30m cooldown. Give it decent melee damage (on or slightly above the early felguards), with the immolate effect for nearby mobs (say, 20 base damage/tick, scalable by lock's +dmg). Remove the "must be outdoors to summon" requirement.

Doomguard: 30m duration, 60m cooldown. Buff armor, defense, and give him a powerful AoE taunt (perhaps replace Rain of Fire with 'Demonic Shout'). Replace Dispel with a heavy threat single-target taunt, leave cripple and war stomp. Put melee damage on par with infernal, but without the scaling. Instead make his armor and HP scale with the Lock's armor (much like Dire bear with druids).

Both demons would not cancel any Demonic Sacrifice buffs active on the warlock. Also, both would never break enslavement before the initial duration was up, but after breaking the normal rules apply (enslave for 5m duration, diminishing returns).

This'd help alleviate the lack of tanks... Doomguard would theoretically be able to take on most 5-man bosses, when aided by a decent group. Hell, even make him immune to Health Funnel so you don't get people QQing about locks soloing group content. But, he's just weak enough that he's useless against heroic and raid bosses.

Just a thought. Pick it apart as I know you will.

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