I've... Done everything I could, TRYING to add an immunity to normal weapons to all of the daedric and ethereal/ghostly races... And while attaching the perks to individuals works, adding a spell effect that adds perks doesn't even, even adding a spell effect that adds a perk that adds a spell effect doesn't work. And I don't know if it's EVEN POSSIBLE to make a spell or ability that resists normal weapons without relying on perks. I wanted to alter the races themselves- because I can't imagine any other possible way, to make sure daedra/ghosts added from other mods are immune to normal weapons if my perk is active.
I remember the other day, I was shaking my fist in anger at an ancient frost atronach who would not become immune to my iron weapons, and I was like "HOW DARE you get hurt when I hit you with my sword, HOW DARE YOU!". Okay I didn't really say that, but I was thinking that.
I even finally figured out how to add spells to the dremora race- turn the disable swimming in combat or whatever it's called off, add the spell, then re-add it again. Could I possibly, even... I don't know, make a quest that starts at the start of the game, and it applies immunity to normal weapons? Can such a thing even be made into a spell effect? Could scripts be added to all of the iron/imperial/steel/wooden weapons? But then, could you make a script that would add that script to every iron/imperial/steel/wooden weapon?
Or is there LITERALLY absolutely NOTHING I can do, other than add the perk to every vanilla daedra/ghost, and simply avoid mods that add new daedra and new ghosts???