Argul's Principal of Death and Life; The Godsworn of Necromancy

You must be at an altar of Argul to cast this spell, of which the altar is surrounded by 1,000 powerful corpses and has a cauldron filled with riches in front of the altar. At the start of casting this spell, a massive wave of blood red mist launches across the entire world, notifying every creature on the planet in every dimension that someone is casting this spell, although does not give a clue on the location of the caster. This spell can only be countered by a wish spell, if the person who is casting the wish can see the caster and cannot be dispelled by any other means other than the caster dying due to exhaustion or psychic damage.

While casting this spell, you become immune to all statuses, besides exhaustion, and all damage types, besides psychic. Every hour, you are dealt 1d20 psychic damage and are given 1 point of exhaustion while casting this spell. The effects of healing spells are halved while casting this spell. 

After the casting time has finished, all creatures throughout every dimension that were considered 'Living' will die instantaneously, while all creatures that were considered 'dead' become resurrected as undead creatures however are classified as 'Living'. This cannot be avoided once the spell has successfully been cast, and the changes cannot be reverted, even by word of the DM, UNLESS this spell is successfully casted again.

Every undead creature in all dimensions, everywhere. Become your minion indefinitely and you can command them, telepathically communicate with them, see through their vision, cast spells through them, and swap locations (teleportation) with them. You are given additional max hit points equal to 1d4 x number of undead controlled if this spell is successfully countered with another spellcaster that casted Argul's Principal of Death and Life.