The final corrupt pony Discord conjures to oppose the Mane Six is none other than Rainbow Dash, in an undead, grotesque form that puts any other horror he's created to shame. While she has no alternate name and is referred to as Rainbow Dash, I've taken to calling her Nightmare Dash or Zalgo Dash. She possesses corrupted abilities and much like her Sonic Rainboom helped many of the cast find their talent, her Decaying Rainboom will destroy hope itself and take away color from whatever its inky blackness touches. The Elements of Harmony won't work on her; there's not a shred of good to be exploited. She is pure, black evil.