Who do you think is the strongest wizard to ever don the fairy tail insignia?

I think its Mavis Vermillon, while she has the image of a little girl, she actually created the Fairy tail guild. Plus the seemingly little girl IMO, until proven otherwise created the 3 great Fairy magics. I'm about to use some twisted logic lol, to prove she created it, fairy law seems to have been used by master and his master and most likely his own master. Fairy Glitter was given to cana TWICE by mavis, and finally she used the guilds bonds to perform fairy sphere, until proven otherwise, mavis created the 3 great fairy magics, plus she has that crazy strategic mind and so much knowledge on Good, Dark or Lost Magic. Plus she's one of my favourite characters lol. Second, IMO is Gildarts if hades is without heart, or Hades with heart,