Majin Bone

Season 1

Episode 1: Visitors from the Darkness

Mysterious holes begin appearing all over the Earth. People blame it on the weather, but we see seven mysterious fighters fighting at the site in a different dimension. The next morning teenager Ryuujin Shougo learns about the strange holes when getting ready for Earth. That evening he is outside when the ground collapses at his friends house. Shougo goes to investigate only to find a mysterious card. He gets attacked by one of the unknown figures, but then the card transforms him into a fighter known as Dragon Bone.