senshin no ken (spirit sword as I mentioned in the post) is spirit/body based.
Not magic based. So Wis, Str, and Dex (Str and Dex mainly for a short bit, as they need some big boosts if you want to do melee anything) will become your friends for a little while unless you don't want to learn a not magic based skill.
Vit will become a nice thing to boost every now and again and Int and Luck can go hit the road, if you really want mike to learn the Senshin no Ken. Its essentially wielding spiritual power through and with one's blade, as the name (Spirit Sword) implies.