Destiny 2 Warlock BuildNezarec, Disciple of the Witness

The main focus on build is to constantly apply all 3 void debuffs to targets

To apply weaken you can send out your Child of the Old Gods or damage a target with a grenade to proc Echo of Undermining. To apply volatile you can damage targets with your power melee or get a grenade kill to grant your void weapons volatile rounds. Unfortunately, the only way to apply suppression on warlock is to use suppressor grenade, so there's no flexibility with that.

After applying any/all of these debuffs to targets, damage them with Collective Obligation to siphon them in order to redistribute them to a larger target (champ, boss, etc.)

During the whole loop, getting kills with abilities and weapons will keep devour up and speed up ability regen though Nezarec's Sin

Armor mods are focused on gaining your grenade as fast as possible as it's the main source to apply the debuffs. Void surge helps with Collective Obligation to melt targets.

Some tips for using Collective Obligation. You can redistribute debuffs to a immune target to temporarily store the debuffs on an enemy. You can also do this on any enemy at the last second of the timer to immediately siphon them.