Zero

ゼロ

Zero is the primary antagonist who aims to harness Giratina's power to move freely across dimensions. He owns a robotic maid named Infi, who manages his mothership, the Megarig. Zero's goal was to rule the Reverse World. He intended to save it from the pollution dumped into it by the real world. He also sought to exploit the Reverse World's properties to exact revenge on the real world.
He was formerly Newton Graceland's student in the study of the Reverse World, but he became obsessed with Giratina's power and resolved to capture it. Using a machine designed by Newton himself, Zero succeeded in capturing and unleashing Giratina's power. He employed the machine to cause destruction in the real world by damaging the Reverse World.
Despite inflicting significant damage, he was ultimately defeated by the combined strength of Shaymin, Giratina, and Ash when he was forced back into the real world, crashing his flying machine into a glacier. Upon impact, Dawn, her Pokémon, and many surrounding Mamoswine froze Zero into the glacier itself, still inside his machine. Officer Jenny arrests him at the end of the film, during the credits.
He makes another appearance in the credits of Arceus and the Jewel of Life, where he is in prison. He is shown being visited by Newton, who possessed a surviving copy of Infi, which he was happy to see.
(from Bulbapedia)