Hmm, I'll think on it. I'll add the feat, as well (the familiar is on there, but the feat is not).
The problem is that you're probably going to do a lot of the same tricks that normal warlocks do -- get Naberius & a bloodline, and take Hellfire Warlock. So, you're basically a blasty warlock who spent some feats on being good at grappling. Is that worthy of a separate build?