Unsure the current setup but changing the wiki.shardsofdalaya.com to a DNS level redirect for shardsofdalaya.com/wiki would be one method of making it happen, right? As far as the cert for shardsofdalaya.com goes at least (unsure the specifics, I always just self sign my ssl cert so you get the dialog/error thing heh).
However, I don't know how many things that may break, if any, vs the ROI type of thing. Depends.
2cp.