Back before 6.0 the best Warlock soloing spec was Destruction. Ember Tap was very powerful, and as it pumped out the most damage, the shields it created with the Soul Leech talent were almost unbreakable.
In a 6.1 world, this is sadly not the case. Ember Tap was nerfed massively, and is pretty much so bad, it’s a waste to use it. Glyphing it and taking the Searing Flames talent improves it somewhat, but not to the point where you’d actually benefit much from using it. Not only that, but losing Health Funnel from the spec means that when your demon starts losing health, the only way to restore health to it is through Soul Link. Sure, Ember Tap restores health to it thanks to the perk you get while levelling in Draenor, but it would take about 40 embers to heal your pet to full from 1 hp, so that’s also terrible.
What does that leave you? Demonology and Affliction both have Health Funnel and Drain Life. When you take the talent Harvest Life and the Glyph of Drain Life, it becomes a surprisingly powerful heal, however as it does rather poor damage, using it is a massive loss to DPS. When in a fight that has a rather tight time limit, this can be a nuisance, but sadly it’s one of the few ways you CAN restore health. What it then comes down to is which spec you do most DPS in. Currently, Demonology is the best performing of all 3 Warlock specs, so at the moment, it’s your spec of choice.
One thing Destruction does have going for it is the ease at which you can resurrect your pet. Demonology requires you to go into demon form then use 200 Fury on resummoning, which is quite a heavy hit. Flames of Xoroth may cost an ember, but you just hit the button and voila! Instant pet! Follow that with a Soulshatter and you’re set.
Other things to consider:
- Mortal Coil has a heal attached to it, but it only works IF your target can be affected by the Horror effect of it. This means that 99% of bosses will render this ability useless. Better to go with Shadowfury on that talent row, in case of add swarms you need to stun!
- Some bosses require you to be 100% alone lest you be stricken by mind control effects and reset the fight. Kael’thas for example. For this, you will need to tank the boss with your face and use Grimoire of Sacrifice, which requires Destruction or Affliction.
- Glyph of Health Funnel is a minor glyph that adds a 10 second cooldown to Health Funnel, but turns the heal into a 15% instant. This is useful on DPS race-style fights where you don’t want your attention off the boss for too long, eg Ultraxion. Stops you having to channel for 6 seconds!
- The Voidlord is a better tanky pet than the Infernal due to the Void Shield ability it has. For this reason, it’s best to go with a talent other than Demonic Servitude.
- For ease of picking up more than one enemy, the Felguard/Wrathguard is a better bet. Have it Wrathstorm and it’ll generally pull threat off everything it touches.
- Mannoroth’s Fury is a terrible talent.
- Dark Bargain allows you to bypass some mechanics, eg if you’re REALLY insistent on having a pet out on Bloodlord Mandokir. Pop DB before he Decapitates and hope you kill him before the 7.5m DoT kills you.
- Don’t forget to Soulstone yourself!
What Warlocks can solo (thus far):
- Vanilla: Everything!
- Burning Crusade: Everything!
- Wrath of the Lich King: Everything bar Valithria in ICC, though this fight can simply be walked around.
- Cataclysm: Everything!
- Mogu’shan Vaults: All bar Will of the Emperor (6th boss)
- Heart of Fear: Imperial Vizier Zor’lok, Blade Lord Ta’yak, Garalon, Wind Lord Mel’jarak.
- Terrace of Endless Spring: All bar Sha of Fear.
- Throne of Thunder: Horridon, Council of Elders, Tortos, Megaera, Ji-Kun, Primordius, Dark Animus.
- Siege of Orgrimmar: Immerseus, Fallen Protectors.
Some of the Mists bosses will need you to be at 650+ item level. Siege bosses even higher! In terms of current content, Kromog can be soloed until berserk (you’d need 78k dps to kill him), and Oregorger has been duo’ed by a Warlock and Death Knight pairing.