Reincarnation 4

Reincarnation 4: Soul Boxing (ソウル・ボクシング!) is the 4th chapter of Shaman King.

Short Summary
To qualify for the Shaman Fight, Asakura Yoh is tested by Silva, a member from the Patch Tribe who oversees the Shaman Fight. However, Yoh is unable to hit Silva, who uses his spiritual energy to combine his various animal spirits to combine with objects to create weapons in a technique named Over Soul. When Yoh finally manages to create an Oversoul by merging Amidamaru with his Harusame, he is able to land a hit on Silva thus qualifying for the tournament. Yoh is soon forced to face his first opponent, an Ainu shaman called Horohoro, who channels his nature spirit, a Koro-pok-guru named Kororo, in his snowboard to make ice attacks. Horohoro dreams of becoming Shaman King in order to create a vast field of Butterbur for the Koro-pok-guru back at his homeland.