I'm liking this tree, although not quite as much as the tainted scholar or enlightened spirit. It looks like a good tree if you're multiclassing or as a secondary tree for tainted scholar. A few questions and comments, though:
- This tree seems rather heavily dependent on having enemies stay alive to work off your consume and strickened abilities (ironic, in a tree focused on instant death spells). I don't think most enemies stay alive long enough to warrant their full usefulness, unless you intend them to work on red and purple monsters, as well. For example, you use consume on an enemy, increasing your movement speed and debuffing the target when you attack it (probably kiting it around). The vast majority of trash mobs are going to die rather quickly with this sort of situation, and they die rather quickly, regardless. I like these abilities because they play on the warlock's unrivaled debuffing capabilities (like in PnP), but their usefulness seems very short-lived. It also seems like a ton of micromanagement and keeping track of what mobs are affected by what debuffs. Perhaps an 'aura' around said mobs, like you see on sickened or diseased players?
- You said the damage from consume and stricken scales with sellpower. What type is used?
- Just to clarify: eldritch projection is a blast SHAPE and would be exclusive, just like eldritch blast/chain/aura/shadow and not an activated attack?
- What is the range on 'Steal Lifeforce'? When you say it's affected by spellpower, does that mean either positive or negative, depending on the type you have chosen? Universal spellpower? Force/impulse spellpower?
- I think somebody said so above, but it needs mentioning, again: be careful that Dark Feeding has the same cooldown as the duration of the buff to prevent overlapping issues and possible exploits. Also, 1d8+2 seems pretty strong for a tier three ability that only costs 2 AP. I'd scale it back to a straight up bonus, like always being +6 constitution or +6 intelligence, etc.
- I would have liked to see the iconic 'Devour Magic' invocation warlocks get in PnP in this tree, maybe as a single target ranged magical attack. Warlock was pretty much the tops when it came to dispelling enemy buffs. Perhaps a 'renamed' mordenkainen's disjunction SLA in tier 4 or 5 with a balanced cooldown to match. If it works, you can maybe gain 20/30/40 temporary HP. It fits perfectly in the souleater's theme.