User blog comment:Jrotc193/Mystogan vs Jellal/@comment-10145146-20130506183327/@comment-7418318-20130507113639

Mystogan's magic seems to come only from his staffs.

Considering we already saw a move that combined all five of them, I think that Mystogan has either already shown his strongest attack or at least came very close to the limit of his powers in his fight with Laxus.

Jellal on the other hand was always somehow stopped from employing his strongest attacks. First Abyss break, which he couldn't cast due to a deep wound from Erza and in the GMG arc Ultear stopped him from using Sema.

But even with his full power not yet revealed, he already used two attacks that killed his opponents with a single hit (an unknown spell against the cult leaders in the tower of heaven and Altaeris against Simon) and unless it is undone the self destruction circle is also lethal (and strong enough to pulverize a rock formation the size of the fairy tail guild hall).