Water Shuriken starts charging when pressing the special button, and is thrown forward when the button is released. The more it is charged, the bigger, more powerful and slower it is, and when charged for a sufficient duration it hits multiple times while pushing the opponent back and ends with some notable knockback (which can be Smash DI'd out of). Uncharged shurikens only hit once and are very quick, making them easy to spam.
Unlike several similar projectiles, the charge of the move cannot be stored.
Special Move customization was added in Super Smash Bros. 4. These are the variations:
Introduced in Generation VI, Water Shuriken is a physical (Generation VI) or special (Generation VII onwards) Water-type move with the unique trait of having +1 priority (like Quick Attack), going before most other moves, while also hitting multiple times in one turn. Greninja can first learn Water Shuriken at level 36, the same level at which it evolves from Frogadier. Additionally, Water Shuriken was one of Greninja's two signature moves in Pokémon X & Y, although it has since been made accessible to Accelgor starting from Omega Ruby and Alpha Sapphire; in Sword and Shield, only Accelgor can learn the move as Greninja was removed from the game.