User blog comment:MarineroLelouch/Power Ranking and Classes./@comment-86.211.93.200-20140210185325/@comment-24066070-20140211184628

Mystogan would be able to use magic in Earthland, since Jellal could still use the staffs (dunno where he got them) and considering all the other mages are in Earthland, there is a possibility for Mystogan to fight them if he comes over (not sure if he can come over when there is no magic in Edolas, which may be needed to open the passage)

As much as I like Mystogan's char, I doubt he was equal to Laxus pre-timeskip. I got the feeling Mystogan used some of his strongest spells right off the bat, whereas Laxus still had Dragon Force up his sleeve. So a prolonged battle would've ended in Laxus' favour I think.