Clarissa's Silvally

Clarissa's Type: Null is a Pokémon she obtained in Alola.

As a Wild Pokémon
Clarissa encountered Type: Null outside the Aether Foundation where Lusamine revealed to her that Type: Null was created to be an artificial Arceus. Clarissa, being the human who represented life, attempted to bond with him but failed miserably.

Upon Team Skull's arrival to the island, he battled against them in order to protect his home but ended up being mortally wounded. Clarissa used her gift of life, something she received all the way back in Diamond & Pearl, and revived the Normal-Type.

While leaving the next week, Type: Null used Headbutt on her in order to get her attention. It rolled a Poké Ball to her, expressing its desire to join her party and was caught.

Sparks: Sun & Moon
TBA

Trivia

 * He is referred as a male