Now I understand that this is a lot of people/demons to account for and there really isn't a way to logically get an answer because of various Time-Skips ect. But it would be interesting just on opinion.
Time of the fight: Alavarez arc
Place: All of Fiore (I understand it's large but there is...
Black Curse(used against erza and minerva)
I Think Mard Geer will win in an extremely difficult fight as his Dea Yggdrasil was potential City Buster and He is more intelligent than Ajeel.Only because of DES They were able...