From Sonic Retro
Black Tornado is one of Shadow's moves in Sonic Heroes. The Ultimate Lifeform's version of the Tornado Jump and Team Dark analogue of Sonic's Blue Tornado, Black Tornado is activated by pressing while in the middle of a spin jump. Shadow then spirals in circles around an enemy, creating a vortex which sends smaller opponents flying up in the air. Larger enemies are disorientated.
The Black Tornado can also be used to send Team Dark spiralling up poles, which is necessary to progress in some levels.