Fura Yabisu was the previous Shaman King. His representatives in the F.O.M. are called Team Yabisu.
His skull can be seen lying on the King's Throne in chapter 277 of the original Shaman King. He shows his face for the first time in chapter 7 of Shaman King Zero, entering the place in the G.S. where Hao resides.
Yabisu hasn't shown his powers yet. He is only said to have reshaped the world into his "Utopia", where money is the most important factor in how a human lives his life.