u/Absolute_Abyss_98

When it comes to artifacts that originally did not belong to any of the princes but later got claimed by one (Like Spellbreaker, Goldbrand and Volendrung), is it possible to purify/remove the influence of the prince from them so it can return to how it was before? And are there any known instances where this happened before?

From Skyrim, we know that there are two ways to enter the Soul Cairn : Partially soul-trapping oneself, or by turning yourself into a vampire. And since vampires being undead can enter the Cairn, I'm assuming other forms of undead (Like liches) maybe able to do so as well.

But are there are other ways in lore for a normal person to enter it? Or any other methods that could potentially work?