Astral Severance

By performing the Astral Severance ritual over an indeterminate number of hours or even days, the caster severs all ties with the outer planes and any beings connected to those planes, including all deities, making the caster permanently out of reach to them. The ritual creates a protective barrier that shields the caster from extraplanar influences indefinitely, even if the caster dies and is resurrected. The ritual can only be cast in the Shadowfell, and upon completion, the caster is instantaneously transported back to their home plane of existence to a random location. The caster has no recollection of the ritual taking place.

The caster loses all divine spellcasting abilities and cannot regain them. Spells or abilities that contact, summon, or bind extraplanar entities automatically fail. The caster can continue to use arcane magic through the Weave as normal, provided the spells do not involve extraplanar components.

There is a small chance that the immense power channeled during the ritual causes a split in the caster’s personality, resulting in a duality where each personality has access to different aspects of the caster's magical abilities. The likelihood of this occurring increases with the caster's level and the imperfection of the mirror used in the ritual. As the caster's level rises, the spell struggles to obscure such a powerful being from the gods without splitting their essence and reducing their impact on the Weave. Similarly, a more imperfectly constructed mirror also heightens the chances of this split occurring. The mirror can not be replaced by a component pouch or a spellcasting focus.

Each personality bears the same physical and mental attributes as the caster, including their appearance. The only exception to the latter is their eye color, which differs and, when combined, would result in the original eye color of the caster. The two personalities are aware of each other's existence but consider themselves to be different people with a close relationship (e.g., close friends, relatives). It is impossible to convince either personality that they are the same person. After every long rest, the caster has an equal chance to wake up as either personality. Each personality retains approximately half of the caster's spell list. These halves are thematically coherent (e.g., from similar schools or with similar damage types) and are as different as possible from each other. Each personality is a different spellcaster that learns or forgoes spells independently.

In the event of a personality split, there is a further 10% chance that the ritual leaves behind a shell of the caster, imbued with remnants of their original essence. Extraplanar beings, including deities, can still reach out to and interact with this shell, having no way of knowing that it is not the caster.