Black Sickle

Black Sickle is a bull spirit and the guardian ghost of Kalim

About
Black Sickle is a large black bull, animal spirit, that belongs to Kalim of the Ten Patch Officiants. Because it still has its original form it can be questioned if it has evolved into a Seirei-Class spirit. It is most like based on the Texas Longhorn species.

O.S. Black Sickle
O.S. "Black Sickle" Description: By using his hatched and the skull and bones from a bull attached to his pants, Kalim can completly materialize the body(except for the tail) of his blac bull spirit Black Sickle onto his legs, giving him a centaur like form. With this OverSoul Kalim gains incredible speed and strenght, that can deal severly damage anyone, also can Kalim completly conroll the bull body. This OverSoul was first seen when Yoh and his friends arrived at the Plant of the Plains, where Horohoro instantly attacked Kalim. After easily crushing the ice, Kalim generated the OverSoul and punched Horhoro so hard in the gut that he was knocked out.
 * Shaman: Kalim
 * O.S. Type: Spirit Type
 * Spirit Ally: Black Sickle(Bull Spirit)
 * Medium(s) Used: Hatched; Bull bones and skull, attached to Kalim`s pants

Anime/Manga Difference
In the anime is Black Sickle represented as a red bull.