Fun concept involving a fallen angel theme...
I got as far as an Aasimar with Scion of Humanity to count as Human, taking Mark of the Devoted at level one. Gave her 8 levels of JuJu Oracle, because it is exactly what Mark of the Devoted is all about, and 3/4 BAB classes do best taken in blocks of 4. Also added 5 levels of Agent of the Grave to retain her intelligence and free will. Then, obviously, I am going to give her a Wendifisa Spear to speed up the transformation to 1rnd (from 1D4 minutes) after her inevitable death at the hands of the party.
As I was reading the JuJu Zombie template, I see it says you can keep your flight if you have wings... hey, Aasimar can have those.
Angel Wings requires Angelic Blood. Which requires a Constitution of 13... would Charisma automatically replace Constitution for this being Undead? Or am I $#!+ out of luck on putting Angel Wings on an Undead Aasimar?
If there is a way to bypass Undead's immunity to bleed effects, would Angelic Blood deal extra damage to an Evil Undead Aasimar with Angelic Blood? It says adjacent, but rules are dumb sometimes (like counting as your own ally shenanigans).
If you have Angelic Blood and Angelic Wings before becoming an undead, you should be fine to keep your wings. You won't get any USE out of Angelic Blood anymore due to your loss of constitution (feat becomes inactive) and because you can't take bleed damage anymore.
The normal rules for undead using their Charisma score for determining HP and for Fort saves (when such saves are actually required) would apply. It does not change the requirements for feats that require a constitution score. The Juju zombies specific text about using their charisma score for abilities that derive from Constitution might apply to feat requirements, provided a GM is lenient about it (I would allow it).