This move appears to be completely original to Smash, as Sheik has never been seen using this move in any other game.
When the button is released, Sheik pulls the pin on the grenade, causing it to explode. When the grenade explodes, it has a vortex effect that pulls in nearby opponents before the actual explosion occurs. The vortex also steadily damages enemies over time. In Smash 4, if Sheik performs this attack in the air, she will enter the helpless state.
If the opponent hits Sheik before dropping the grenade, it will fall to the ground. This item can be picked up and used for comboing. Grenade deals 6-8% damage when thrown.
Special Move customization was added in Super Smash Bros. 4. These are the variations: