Apocalypse Malevolente

The spell's description

No other spell with such a destructive power has ever been created within the realm of magic as a whole. Legends have been written about it and it's supposedly effect of world annihilation that has never been experienced by any creature, magical or not. The result of magical research that has gone completely wrong, as the creator intended for the spell to be a world-creation spell, however, despite his legendary status of knowledge within the realms of magic he's managed to turn what he thought would be a beautiful showcase of the capabilities of magic into a realm-ending tool.
The spell's rarety is beyound any other due to it's catastrofic consequences and it's legendary status, so much so that many magic-users regard Apocalypse Malevolente as a mere folk-tale. There only exists 1 scroll containing information about the ritual needed to cast the spell and it's hard-to-get components, information that even the most powerful wizards of our time have yet to uncover from other sources that ever so slightly describe how it came to be, but never it's exact effect.

Important notice

Apocalypse Malevolente can NOT be selected by a player when leveling up, and usually it is not intended to be used by players, although the possibility exists. It is intended to be used by villains most of the time as a way to place a sense of extreme urgency in world-ending scenarios. The spell can NOT be reverted by a wish spell, once active, it's effects take place and are definitive.

The spell can be found in a incredibly hard to get in room in a high-level dungeon; if, for any reason, the game master wishes to randomly roll fo the existance of the spell in a random dungeon, they must roll a 5% in a percentage dice to define if the secret chambers that guard the scroll exist within the dungeon and then roll a 1% in a percentage dice to define if the spell wasn't taken away from it's chamber.
Notice that the rules listed above are only for the placement of the scroll in random dungeons created by the game master ONLY if the game master themselves want to insert the spell in a random dungeon.

The room of Malevolente forces - Not recommended for player reading

The room that guards the spell is completely made out of bricks of vulcanic rock, a pedestal with the magical scroll stands firm in the middle of the dark-fiery hot room, lava running through the gaps between bricks within the floor and strips of gold that decorate the walls by spelling different curses in a unknown language that either a high level rogue can try to decipher for a 65% chance +5% per level above 9 (Max of 95%) and a comprehend languages spell can try to translate the gold writings on the wall with a 45% base spell failure -5% per spell slot above 1 used to cast the spell.
The writings on the walls themselves are part a guide on the dangers that await anyone who so desires to acquire the spell Apocalypse Malevolente.

1. "The ground burns with the rage of the earth" (Any creature stepping on the floor recieves 2d6 of fire damage per 5 feet moved until they step out of the room's floor, the same applies if creature has fire resistance; only immunity may negate said damage).
2. "The air is condensed with the guilt of a heavy soul" (Flight in the room is impossible, being natural of magical flight; any creature that tries to fly instantly fall to the ground and receive 4d8 of fall damage, even if the distance between the creature and the floor are minimal).
3. "The soul is tasked to endure the cruelty of misfortune despite it's wonderous talents" (Any sort of magic has a 45% chance of failure within this room, -5% for every level of spell slot beyound the minimum needed to cast the spell used to cast it).
4. "For only brave and mischievous hands may, or may not, succeed on unraveling the knowledge" (Only characters of evil alignment may touch the scroll when it's inside the room, any other alignment may do a wisdom save (DC 25) or fear the usage of magic for the rest of their lives, only a wish spell is capable of reversing this curse).

The spell's effect - Not recommended for player reading

Apocalypse Malevolente, despite it's name, isn't nescessarely about world destruction as some would assume. It's existance is supposed to be a tool for story-telling rather than a spell that will be activelly used by the players, however, the possibility is open if so desired by the game master. The spell's effect depends on what the Game Master desires it to be within one of the following three effects listed:

• The spell does not cause world destruction but merely the illusion of the world being destroyed for the magic-user who casts it. Everything around the caster is, in their perspective, completely destroyed and turned into nothing but void. In reality, the caster seals themselves in a void created by the spell for the rest of his existance, being unable to be contacted or taken out of said void; this is definitive, and even a wish spell can not bring the caster back.
• The spell does cause world destruction, but, only of said instance of the world. While yes, it does obliterate reality as the intended effect of the spell, it only does so at the exact moment that the spell has been casted; meaning that, reality itself keeps on going within an alternative universe where it was never casted by the magic-user by a variety of reasons or perhaps in a alternative reality where the caster never got hold of the spell in the first place.
• The spell does cause world destruction. Once casted, nothing can be done about it but acceptance. If the game master desires to take this outcome, they get the opportunity to reset their world by any shape or form that they desire; it isn't advised to take this effect for the spell but the possibility is open.