Nah, thats kinda the theme in FT.
You can be so strong that you stomp a character from FT guild for like 10 battle, then on the 11th they suddenly got massive power boost that suddenly dwarf you and you lose to them and that's it. Even DBZ have more flow in power boost then FT.
It's literally just the power of plot.
Let me put this in a better standing then:
Natsu when he killed that War God in one punch had an entire arc that was him and the other members of Fairy Tail fresh out of a training arc to deal with Zeref and his Spriggan 12 and they absolutely demolished their opponents without even a single issue whatsoever. There was no legit plot or anything that had Natsu do that, it was explicitly done to show how strong Natsu and Co. are now and how strong their future adversaries are.
Nothing shows that DiMaria or Chronos is any stronger outside of her dealing with Wendy, Lucy and someone I forgot. That's the point I'm making here(Especially since DiMaria's whole thing is taking over random Gods' for their special abilities.
Can't really believe single fanfic can shaken some fairy tail fans.
It never stops being funny when people have to literally fan-fic fights just so who want what they win does over that same thing. Morgan in character does love to fight but she isn't stupid enough to pick fights she cannot win and DiMaria in character is a sadist on her worst day meaning she would try and torture Morgan to death and die from that. Hell in character, the Spriggan 12 would be the FIRST she would demolish just to get them off the board. It's also funny that dude acts like that "Fairy Tail Mages have hax and shit" when Fairies in the Nasuverse has hax in spades and that's just for the grunts and Morgan didn't just defeat the grunts but even the Godmother/Godfather classes and the A-Ray Class at the peak to rule Fairy Britain.