Speaking of power creep, I -sicerely- hope they fix the Dark Pact before press.
The problem is, not only is their bonus overpowered (damage = D6 x pact boons, holdable for an arbitraraly long time (keeping in mind that you never -have- to take a long or short rest), automatic hit, Immediate Interrupt? Excuse me? Compared to Fey Step, +LVL Temp HP, and (closest, but...not so much), +1 to hit per boon, only usable this or next -turn-), it also encourages a really bad style of play -- where you fight every combat you can, seeking out below-level encounters if the GM lets you get away with it, until your Dark Warlock is charged up with, say, 40 boons or so. Then send Mr. Warlock out to solo the Big Bad--unless BB can kill him with area and Close attacks, or is immune to both Psychic -and- Necrotic damage, he's toast, as his first targetted attack on the warlock gets interupted with a giant sized Blast of Doom, which not only halves his damage, but assuming you've done your planning right, probably kills him.
At the very least, Darkspiral Auras -must- reset to 0 every 5 minutes; letting you power up on the bb's crunchy minions before bluffing him into attacking you and getting do some free damage is cool. Bringing in a herd of sheep into the dungeon with you so you can curse them in turn before your big fights and bring a Death Sheep-powered can of whupass into a laser-fight? Not so much.
I'm not sure who to email this to in Wizards, but it should certainly get complained about before FR goes to print -- we really don't need a Warlock who's not only better than any other Pact, but needs to heavy hand of the GM to keep in line.