>>538795597
>But do undead holy priests not use the light to heal?
Canonically, they don't exist or didn't exist. Player characters using holy was just something they left in, but every priest undead NPC should be considered shadow until about.
using the light hurts undead, and being healed by it also hurts them as it heals them.
When legion was added, we got Alonsus Faol who is the first non-shadow undead priest, he's disc, then all of that gets kinda undone when they introduce Calia Menethil and a light touched undead, and I'm pretty sure she can use holy magic with no drawbacks.
For like a long time, the only notable undead who actually used holy magic was sir zilek of the 4 horsemen.
Really the entirety of it is a mess and not worth thinking about too hard.
TLDR: they can use holy magic, but they prefer not to because it's painful to use and painful to recives and if you do either you're basically a giga chad. Unless you're calia menthil who is a magic undead.