Vampire Corruptions
Unless you're a High Elf, you should be able to get these by drinking potions of corruption. If you're a High Elf, you should get a message to the effect that you resist Morgoth's corrupting influence.
Demon Spirit
Increases your INT by 4... And in addition to the CHR malus, cuts your sanity by 15%. Nobody ever accused demonologists of being sane.
Demon Breath
At level 40, provides plasma breath, not fire, and for higher damage... But doubles the chance of potions not working.
If we have a breath attack, it shouldn't be a parlor trick, but there should be bigger disadvantages.Troll Blood
Get rid of the aggravation, replace it with a large stealth malus. Yes, I know this is pure advantage; but Troll Blood isn't a particularly powerful corruption, so it shouldn't have such a tremendously bad disadvantage.
Random Teleport and Anti-teleport
Get rid of 'em.