I'm not against adding Ebisu to the relic list, but the question is if we add Ebisu, what else do we then have to add? There are a ton of other hard to get items out there:
Ninurta's Sash
Black Belt
Novio Earring
Dorje (Whenever we learn how to get it)
If we add Ebisu, I think we outta add some or all of the above items. They are as equally hard, or even harder then Ebisu.