User blog comment:B214/Volume 17 spoilers./@comment-49.147.47.247-20140406024955/@comment-1359322-20140406082532

Undoubtedly Sirzechs, Grayfia is only Maou-Class at best, Sirzechs is on the Top 10 of the world from all mythology, he's a dozen time stronger than Grayfia, so of course it's the same situation with Euclid.