I have Necromantic ferver located, but not vital ward. When a volatile zombie dies, I get ward. I am not sure if I get health or not (no way to test it reliably)
My character doesn’t have Reclamation of Soul, so shouldn’t be that. I have 1 point in Mania of Mortality, but I can realiably trigger the ward gain on every volatile zombie explode, definitely not just 10 percent.