I'm looking into the corruptions, and one of the Lich corruptions gives the following gift:
Deathless Gift:
You gain a +2 bonus on saving throws against spells and effects that work only on living creatures.
That seems a little unclear to me, does that mean things such as charm person and other mind-effecting things also have the bonus applied to them? Or other things that do not affect undead - I'm really not sure what spells that "only works on living creatures" applies to.