Quoted By:
Holy shit, it's one of the coolest Water type designs in a while with some insane lore.
From Bulbapedia:
> Basculegion's evolution is said to be achieved by Basculin being possessed by the deceased souls of other Basculin in its school who did not survive the harsh journey swimming upstream. When it senses danger, Basculegion will turn hostile and attack along with its souls until the enemy is defeated. The souls within Basculegion are said to have a will of their own, and provide Basculegion with the power needed to swim on without tiring.