Shaman King, Sousei no Onmyouji Recommendations
Aside from being under the same genre - action, supernatural and shounen; the two have other notable similarities:
1.) The male and female protagonists on both shows were destined to be husband and wife, also as being agreed upon by their family/superiors; which later on turned into real romance between them.
2.) The male protagonists have the same dream of becoming the strongest - for Yoh to be the Shaman King and for Rokuro to be the strongest exorcist like Abe no Seimei.
3.) As for the female protagonists, Anna and Benio - both are very powerful and very supportive of their partners which makes them very reliable