Title: Death Battle: All or Nothing

Main Characters: Rainbow Dash, The Mane Six, Spike, Others.

Genre: Adventure, Comedy, Crossover.

Crossover With: Death Battle (and many other franchises)

Premise:
Throughout the cosmos, there millions of worlds with many powerful warriors, some of them the greatest of heroes like a speedy blue hedgehog or the last survivor of an alien race, others the vilest of villains such as the demonic ruler of Outworld or a powerful freelance assassin. But in the farthest reaches in the galaxy, two creatures with powers comparable to gods have watched these exploits-both good and bad-for centuries, and have constantly pondered one single question:

Who would defeat who in a Death Battle?

Knowing the only way to settle this debate, they proceed to teleport two similar warriors from their respective universes and pit them against each other in a one-on-one Death Battle, with a few rules:

1: No outside help allowed. Summoning other combatants is not allowed unless the battle requires multiple fighters on each side.
2: Pacifist warriors will not have their peaceful nature interrupt the fight, and both combatants will have any personality restraints from killing removed.
3: The terrain chosen in the fight will either be a terrain from either fighters' world.
4: The winner of the fight is granted their opponents weapons, armor, and skills. If their opponent has any inherent abilities, they will be integrated into the winners body structure.

As such, the Death Battles begin as many heroes and villains are slain and victorious throughout the the fights. However, one of the warriors known as Shao Kahn ends up becoming more powerful than before and starts ripping holes across dimensions and amassing an army made up of the villainous victors of the previous Death Battles, becoming so powerful that even the two gods are unable to stop them!

With no other options and the universe in danger, they set their sights on the heroes of the previous Death Battles in hopes of them evening the odds and saving the multiverse, one of them being a representative from Equestria: Rainbow Dash, with the powers of her fallen opponent; Starscream.

However RD’s friends won’t simply let her go at it alone, especially with Equestria on the line! Together the mane Six join her her adventure across the cosmos to save the multiverse!