A quick search through the Discords shows a general disdain for the current state of Eldritch armor. The cost is high and the tradeoff isn't exactly worth the trade. Here, a rework is proposed:
Firstly, shift the Expertise and Improved Expertise passive to the Hideous Blow feat. This will allow Warlocks that use said feats the ability to survive a bit more in PVE while they build their character.
Eldritch Armor is a radial.
Eldritch Armor has charges.
On use, a charge is consumed.
The first option is like a poor-man's divine shield. When activated, the warlock gains half of it's CHA as AC, instead of the full sum.
The second option like half of divine wrath: When used, gives additional damage immunity (akin to the DR from wrath)
The third option is akin to the offensive portion of divine wrath (or divine might). On use, it gives extra damage die to Hideous Blow (like the +divine damage)