Gul'dan

Gul'dan was a former orc shaman from Draenor who became the first orcish warlock as well as the de facto founder of the Orcish Horde. Abandoning the ways of shamanism and betraying both his people and his mentor to the demonlord Kil'jaeden for personal gain and power, Gul'dan was directly responsible for the orcs' fall to demonic enslavement as well as for the Horde's invasion of Azeroth. Tutored by the lord of the Burning Legion, he became the founder and master of the Shadow Council as well as the original creator of the necromantic terrors known as death knights. He often referred to himself as "Darkness Incarnate" and "The Destroyer of Dreams." Gul'dan is considered one of the most powerful warlocks to have ever existed.
[FEAT] Chaotic Energy - Quest: Gathering a Regen Globe causes your next Basic Ability with a Mana cost to refund 40 Mana. Reward: After Gathering 20 Regen Globes your Basic Ability Mana costs are permanently reduced by 20.
[FEAT] Consume Soul - Cooldown: 30 seconds Instantly kill an enemy Minion and heal for 800 (380 + 4% per level) Health.
[FEAT] Hunger for Power - Increases Ability Power by 15% but reduces healing received from allies by 25%.
[FEAT] Dark Bargain - Your maximum Health is permanently increased by 25% but your Death Respawn time is increased by 15 seconds.
[FEAT] Healthstone - Cooldown: 60 seconds Activate to heal for 25% of your maximum Health.
[FEAT] Demonic Circle - Cooldown: 1 seconds Summon a Demonic Circle at your location. Activate to teleport to the Demonic Circle.