Here are some of the Shaman King pairings you can choose to play.
. Yoh/Manta
. Ren/Yoh
. Ren/HoroHoro
. Ren/Lyserg
. Hao/Ren
. Hao/HoroHoro
. Marco/Hao
You can choose other pairings if you wish. These just happen to be some of my favorites (except Ren/HoroHoro). I just put that there.