So for Yoh Asakura: Amidamaru probably needs to be custom made. His abilities fall all over the spectrum. I am looking at a 2-3rd level vestige so far with the guidelines from WoTC.

Seeing that virtually all the Shaman King fellas have at least 2 levels in OA shaman, to be able to see ghosts constantly; not finding any other ability (outside of shaman's spirit sight) that allows this.