The Dark Helm on the Lord of the Damned in the Ashbury Castle not only permanently increases your evil allignment, it also permanently increases your magic allignment as well. All other Dark Helms that I've found have only boosted your evil allignment, not your magic.
You're most certainly not the first one to find this out Vorak, though I was unaware there were more Dark Helms than that one. I like to use it on followers like Sogg and Loghaire to make them less whiny and add to their benefits from magick gear.
Stop making pointless threads like this, that way people can stop answering them with one post saying you’re an idiot.