Sombritis

"Rainbow Dash!", cried Derpy.

"SO YOU TWO HAVE BEEN CURING EVERYPONY WITH YOUR LITTLE TOYS?!" Rainbow Dash roared. "I JUST WANT TO TELL YOU THAT I AM THE LEADER OF THIS WORLD!! SOMBRA HIMSELF RECRUITED ME TO TURN EVERYPONY INTO THESE BEASTS! I TURNED TWILIGHT FIRST, AND THEN SHE ATE APPLEJACK'S FLESH!! NOW I WILL CONSUME THE TWO OF YOURS!! YOU TWO ARE THE ONLY SURVIVORS! ONCE I FINISH MY FEAST ON YOU TWO, ALL OF EQUESTRIA WILL DIE!!!"

"We will stop you!!" screamed the doctor passionately. "Me and my assistant will win in the end!"

"GOOD LUCK WITH THAT!!!" Rainbow Dash laughed maniacally.

"FIGHT!!!!" screamed the doctor once more.

The two ponies each let out a ferocious battle cry and charged toward the remaining infected ponies. Energy blasts rippled throughout all of Equestria as the final battle commenced. As the battle drew on, Doctor Whooves found a clear shot opening at Rainbow Dash. However, he was down to his last cure bullet. Knowing that Derpy had run out of ammo, and knowing that if he missed, Equestria would perish. With his eyes closed, and his ears focused, Doctor Whooves took the shot, but not before letting out a Latin cry:

"ULTIMUM REMEDIUM!!!"
(Ultimate Cure)

The shot hit Rainbow Dash dead center, and the resulting explosion created a blue shockwave that vibrated the whole planet.