after just a quick glance I noticed one card that stuck out as missing, Mikaeus, the Unhallowed deserves a spot in this deck. I'd remove undying evil for him since it has a very small impact in a multiplayer EDH format.

maybe add restoration angel and exquisite blood?

If you add Exquisite Blood you should also make room for Sanguine Bond as running both is gg once you gain life or an opponent loses life

Thanks for the comments, but currently I'm not willing to invest much into this deck, therefore it could be missing some good stuff, like Mikaeus, the Unhallowed & Restoration Angel .

Exquisite Blood is arguable, since it can bring attention to you at the table, and opponents attacking you mean no life gain from it, but a life loss :-D Subversion might be better with 3+ opponents.

Sanguine Bond is good in decks with lot of lifegain, this deck isn't the cause. Possible interaction with Exquisite Blood doesn't justify adding it here.

About Undying Evil in EDH: it has really good interaction with wrath effects and being the only one with a fat creature on the table after board sweep is nonnegligible in any format. Plus it interacts with Grave Pact /card:Martyr's Bond/Butcher of Malakir .

Anyway, I need to play more games with this deck, to find weak cards/spots.