User blog comment:Sting Eucliffe/Ten Wizard Saints/@comment-3290324-20120712173518/@comment-4951838-20120713025743

Erza said once that Bob was in the same level as Makarov, so I think he's also a Saint Wizard. All the guild masters seems to be stronger than all of the member in the guild, including the Ace (Makarov > Gildarts), so I think that Ooba is a Saint Wizard too. :D