Abyss

Abyss, known as the Armor of Erosion, is the antagonist in Marvel vs. Capcom 2: New Age of Heroes.

Smash Bros Lawl Ultimate
He is the Final Boss in Classic Mode on Normal Difficult. In the first stage of the battle the metal sphere surrounds itself with a giant suit of armor which is slow moving with powerful attacks. The fight takes place in a large temple like structure, presumably underground.

After this form is defeated, the armor melts into the floor and the temple crumbles, leaving the fighters standing in a green pool of slime. The abyss sphere floats in the background as the second form reveals itself; a small green humanoid capable of creating paralyzing bubbles, shooting fire and energy beams, and sinking into the floor to avoid attacks.

After this form is defeated, the green slime turns red and a large demonic beast forms around the Abyss sphere. This third form attacks with powerful energy attacks and sheer brute strength. If this form is defeated the sphere apparently loses its power and the cave and island the monster inhabits begins to sink.