Victini is a legendary Psychic/Fire-type Pokémon. It is known as the Victory Pokémon. Victini has the ability Victory Star, which boosts the accuracy of its allies' moves and status effects. Victini V forms are exclusive to Pokémon Sword.
Other Victini have different Forms depending on their game of origin:
Victini X in Black 2 and White 2 has the V-Create Ability, allowing it to boost the power of its Fire-type moves.
In Pokkén Tournament, there is a Shadow Victini that can be unlocked. This forme has the Dark Aura Ability, which powers up Dark-type moves for all fighters when it appears