Kaiō-ken

Kaiō-ken (界王拳, Fist of the World King) is Goku's down special move in Super Smash Flash 2. According to developers, Goku powers up, giving himself a red tint that ups the power of his next special attack, similar to a Semi-Final Form. The attack also gives Goku two new Special Moves: The Kaiō-ken Attack and the Energy Release. The effect worsens with succession and Goku may even take damage after using it too much.