Pfft, forget sunsinger. If you wanna use a warlock, use voidwalker with voidfang vestments. Grenades can fill in around 8 seconds, and nova bomb can charge fast, with the right skill tree settings, and with the vestments, you spawn with full grenade energy. I can go head to head with any class in crucible on voidwalker, and wreck crowds in pve, and all without relying on burn damage