((Gawdly))

Like some candy-colored apocolypse, the lines of Pokemon clashed, small wings, hands, claws and other Poke-parts went flying through the air, multi-colored blood flying everywhere. Mewtwo stood in the middle of the carnage, looking down at the little ones. As the "good" Pokemon entered Mewtwo's sphere of influence, their eyes glazed over, and they began attacking their former friends. Mewtwo had grown too big, too powerful and his pure evil dripped from his pores, easily swaying the weak minds of the good Pokemon.
Swinging his house-sized claw, Mewtwo knocked the smaller Mewtwo and his partner for a loop, smashing them with such force that they were still gaining speed a mile away.

Mewtwo's army had now tripled, all the newly mind-controlled Dark and Ghost Pokemon filling his ranks. The city was dead now, and Mewtwo still hungered. He could smell the hearts of millions of humans nearby. A large city, a metropolis, teeming with meat. Mewtwo hungered.

((Coreworlds))

Mewtwo and Mew crashed into a building, but they were not yet out of the count...

--

The two Legendaries are then aided by the Dark Pokemon, as they are immune to the mind-control. Fighting the Pokemon army that now is against them, they try to attack the evil Mewtwo, but their powers aren't enough.

So, from the depths of the ocean, a whirlpool starts to form, as a dark shape swiftly rises to the surface, and another shape flies from a mountain range. Sensing the evil Mewtwo, they arrive just in time to see the army try to fight off the evil Pokemon: Luiga and Ho-oh! Tanks rumbled and artillery roared. Helicopters either reported the breaking news or shot missiles and other weapons at the giant cat. Millions began to evacuate the city, but the traffic jams meant that all they could do is run.

Giovanni smirked as his latest creation runs rampant, unstoppable this time. "Unlike my predecessor, I made sure that I can control this beast, and kill whomever I wish to kill. Anyone who wishes to defy me will find themselves in the Mewtwo's belly."

In the meantime, the four Legendaries resumed the attack on Lord Mewtwo, Psyching up (think when Mewtwo and Mew powered up and unleashed a psychic attack at each other, and turned Ash into stone in the first movie) and unleashing more powerful attacks than before, dodging all the while. The Dark types used all the dark and other moves in their arsenal to fight the tide of Pokemon that threatens the city.