Tier 1 (Heroic) Warlock Feats
Soul Harvest: Your demon pets automatically heal to their full HP after a short rest.
Sacrificial Pact: Whenever your demon dies, it’s soul is transferred to you, and you can spend a healing surge.
Student of Malediction: Whenever a creature takes damage from one of your Save Ends effects, you gain temporary HP equal to the amount of damage that creature took.
Dark Intent: You can use Intelligence for your initiative modifier instead of Dexterity.
Cursed Advantage: You gain combat advantage against any enemy your demon is adjacent to.
Kil’Jaeden’s Cunning: Whenever you deal Fire damage, you can shift one square as a free action.
Tier 2 (Paragon) Warlock Feats
Critical Darkness: Whenever you critically hit with a power that has the Shadow Keyword, the target suffers a penalty to all defenses equal to your Intelligence modifier until the end of your next turn.
Inevitable Doom: Whenever you miss a target with a power and deal no damage to it, you gain a +1d6 bonus to your next damage roll against it made before the end of the encounter. Each time you miss the target with the attack, increase the damage bonus by 1d6.
Student of Mannoroth: Once per day when you use a warlock daily power, you regain the use of that daily power at the end of the encounter.
Shadowfury: Whenever you roll maximum damage possible on a damage roll, the target is dazed until the start of it’s next turn, and you can push the target 2 squares.