serious question for all the lore-experts: azura’s star is a soul gem. and trapped souls go to the soul cairn. but do souls trapped in azura’s star also go there? and if so, how is azura connected to the ideal masters?
Seeing a lot of people in the reblogs talking about this but nobody mentions that the question starts out wrong.
Souls do not go to the Soul Cairn by default! Serana is citing her mother's research and she made a mistake, one which Valerica later corrects, and which is contradicted by existing lore to begin with.
Trapped souls are trapped in the gem until spent to power an enchantment, a spell, or until the gem is destroyed. In all of the above cases, the soul is directly used up to do just that. If you're powering an enchantment, that soul will end up inside the item as its power source. If you're powering a spell, you're burning through the soul's life force until it is destroyed. If the soul gem is destroyed, the soul within is destroyed either.
In no situation does a soul ever "go" somewhere afterwards.
This is part of why necromancy and soul trapping is considered so abhorrent. You aren't just trapping a soul, you're also completely stealing away any chance it has at an afterlife.
The Ideal Masters, just like any other Daedra Lord, receive their souls from offerings made by the people who worship them or seek to make a deal with them. Valerica explains that in exchange they receive powerful spells, servants, knowledge, or energy to power complex rituals.
But this is not the default route for enchantment! Nobody does this except for a very small percentage of necromancers.
So to answer your question, a soul trapped in Azura's Star will remain inside the star until it's used for an enchantment, in the process of which the soul is instead imbued into the target item to power it.
