Greetings! And some questions

[Duke Arioch]

Thx for suggestions. However, lawful evil is a must. It is something I built my whole character around. Nine Hells of Baator, devils, hellfire and all...
I think warlock is feat-starved as is, and I do want to take many extra invocations, as I really want to get Shadowmaster and Eldritch Sculptor epic feats. So, feat chains are out too. Ofc, I will swap out some of invocations I won't use anymore (entropic warding is out before I get shadowmaster, for instance).

 

[FEADIN]

If you want to take more feat why don't you take flaws another way to show you're frail while keeping a high CON?
Think you can take two and get two feats that way.
Character Flaws :: d20srd.org

And I like your background, always liked Erynies, get one at home and....well huu.