Final “wish”: A “wish” spell that changes the casters perception of reality. The spell does nothing to the real world other than make the caster go mad. Some people think it’s a wish granting spell that makes those weak of mind go mad or that the caster ascends to a different world leaving there body behind. But in reality it simply breaks there mind trapping them in a fantasy indistinguishable from reality forever seeing the world as if it really was a Wish spell and had worked. They still move and talk but can not perceive what is actually happening.
Ex: I wish for a ham sandwich.
Result: They sit there with a ham sandwich and the world carry’s on as it would but the caster now sees a ham sandwich that they think everyone else can see. It may do nothing or a king could slip on it and die.
For the caster the wish may as well have actually happened and every small change the wish would have caused would change how they see and feel the world. If a wall is in the way that wouldn’t be there if the wish went though they would walk in place as if there was nothing there. Dying in reality or in the fake world would kill them ending the spell.