He-man/She-ra

The worlds of Eternia and Etheria are both front and centre in the war of good and evil. As given the names of sides of their major fractions.

Heroic Warriors, or Masters of the Universe, Versus the Evil Warriors.

The Great Rebellion Versus the Evil Horde.

Even the Galactic Guardians Versus the Evil Mutants.

When you have people fighting, and one side has 'Evil' in it's name, you can see the battle of epic morality. So each side getting one person to convert the members of the other team to their faction, things will change.

Starting with...