I'd love to know if Blood Kineticist + Overwhelming Soul is a legal option, as it would be very thematic for vampires and dhampirs. I found a few vague references in some old threads that it was, or was intended to be so, but nothing official. However, the wording of the abilities gives me pause since it appears that they both alter wild talents, but it's just fuzzy enough to give me a glimmer of hope. Relevant text:
This ability replaces the 6th-level utility wild talent.
This ability replaces the 8th-level utility wild talent.
This ability alters the kineticist's class skills and the key ability score of wild talents.
OSoul specifically calls out that it alters the key ability score (rather than altering the full class feature wild talents), so it stacks with blood kineticist, which replaces two utility talents.
The do stack, but RAW it doesn't do what you want it to, because the Kinetic healer talent which has no effect on undead, however in a home game you could easily house rule that it activates the void healer talent instead; whis dose heal undead.
Thanks for the quick response, Mark! That's great.