User blog comment:IamJakuhoRaikoben/Sorcerer Magazine, Issue 47: November 2015/@comment-1153699-20151206204316

From what we've seen of him, Mystogan really wasn't all that impressive compared to x784 Laxus Tiers. Laxus was holding back quite a bit when he and Mystogan fought and the former still seemed to have the upper hand (and that was after Laxus wasted a good amount of his Magic on Thunder Palace). It is possible Mystogan was holding back a lot too, but we don't really know for sure because the guy never had a serious 1v1. That being said, I personally put him somewhere between Erza and Jellal overall. Seems like a safe bet imo.

But considering how strong everyone (good and bad guys) got after Tenrou arc, I'd say Silver dominates here.

I mean sure, if Mystogan was still around and would have trained hardcore for 3 months or had his SO unlocked, he would probably win (Silver would still give him a good fight though). But unfortunately, that's not what happened.

So yeah, I gotta go with Silver on this one.