Revamping The Undying patron (with invocations!)

[Krumpits]

So for a while I've been looking around to see if anyone had "fixed" The Undying patron to bring it up in power a little while still keeping its highly thematic abilities. Obviously I didn't have luck in finding that, most reworks replaced all of its abilities entirely (which is fair, just not what I was looking for.)

So I set out to have my own crack at it. I kept the base of its abilities the same, while trying to just ADD to them to, hopefully, come out with something myself and other's could have more fun with.

I made some changes to the spell list to try and cover more classic undead-ey themes, and expanded on that a little with the invocations as well. Got a bit of necromancer, grave keeper, vampire and death in there. But I'd also love to hear some suggestions for more, or fixes/balancing concerns on any of the changes I have made.

Link to the rework: http://homebrewery.naturalcrit.com/share/BJUHZGlQ7

[Potato_Priest]

"Revamping", eh?
The class features seem alright, but all three of the pact specific invocations seem lackluster.

Life Sap: I would almost never choose to deal necrotic damage, since way more things are resistant or immune to necrotic damage than are resistant or immune to magical piercing, bludgeoning, or slashing.

Crawling Claw: Correct me if I'm mistaken, but a crawling claw is in most respects inferior to the other familiar options available to pact of the chain warlocks. Advantage on perception/investigation seems like a non-obvious benefit (as in, I don't know what the fluff justification for it is) intended to make up for the mildness of the extra familiar option. I think it wouldn't be totally out of line to allow the chain warlock to get something as powerful as even a zombie or skeleton as a familiar for the high price of an invocation.

Power Overwhelming: This one is better than the others, but we need to really take a look at the warlock's spell list to see if it plays out. From what I recall, warlocks don't get a lot of big damage spells, and even fewer of them deal big necrotic damage. Even if there were many such spells on the warlock's list, a warlock would be much better off taking the elemental adept feat which grants the same ability at will, and with the extra ability to override resistance. While an ASI is generally worth more than a warlock invocation, they aren't worth that much more.

[Krumpits]

"Revamping", eh?
The class features seem alright, but all three of the pact specific invocations seem lackluster.

I do like a good pun! ;D

Life sap: I was trying to make something flavorful, without making it overly strong. I do agree that it isn't very strong, but I'm not really sure how to make it better. If I up its heal on crit, I think people will knee jerk reaction at seeing a big potential number, and if I make the heal non crit reliant it becomes way too good.

Crawling Claw: This one I actually am not a huge fan of. Thematically I think it's fine, but I was trying to follow as close as I could to the format WotC is using. Which unfortunately is an invocation for a new familiar. In attempt to make it more appealing I gave the lock advantage to detect hidden/invisible when the claw is on you, because crawling claws have blindisght. (Taps your shoulder and points type of thing, you'd seen in like the Adams family.)

Power Overwhelming: I agree 100%. It's original iteration was once per rest you could max out necrotic damage of a spell, but I wasn't sure if that was too much, so I knocked it down a bit.

Thanks for the feedback, any other suggestions with the other invocations/class features?