@Darklord#10 @Steven
My thoughts regarding this topic.
I think Mashima doesn't know what he's doing.
On one side, he is somewhat regretful about the constant "power creep" and wants to reign it in. Some examples - Natsu saying healthy Makarov (at best Warrod level) would be far stronger than the possessed version who pushed him, implying healthy Makarov is at least x793 base Natsu level. Spriggans being treated as still kinda relevant, implying they aren't fully powrcrept. Constant comparisons to Gildarts (likely x792 version). Return of Zero as an actual force. Etc
On the other hand, the entire spinoff is set for power creep. Going from a setting in x792 where the ceiling for protagonists was Zeref, to a setting in x793 where ceiling is dragons relative to Acnologia (at least in stats).
Mashima even recognize this, hence the constant mention of characters getting stronger, deliberate nerfing of dragon gods till this arc in an attempt to make their defeat make sense while having the protagonists grow. Etc
Mashima has lost completle control of the powerscaling. He has contradictory wishes, which shows. The manga is full of contradictions and nonsense.
IMO, the only way to make sense of all this, is to assume that Mashima is slowly RETCONNING powerscaling, to REDUCE the gap between characters from various arcs.
While hierarchy is maintained, the gap between Zero to Makarov to Spriggan to dragon eaters to even the dragon gods has shrunk. Contradictory yes, but then again Mashima doesn't know what he's going anymore. DF Natsu is or will be above all will be a constant.
.........
Coming to Gildarts, Laxus, Jellal.
They are very obviously treated as the peak "humans" in the good side (Natsu the obvious exception). With Gildarts the obvious strongest, followed by Laxus/Jellal.
GMG portrayal. To Zeref expecting Jellal or Laxus to reach him, which is Mashima outright stating these two are the strongest good guys (Gildarts was a wild card which wasn't planned).
Coming to August.
In pure combat ability, Gildarts was a match for August. The difference mainly came from the magic immunity. By extension, this would apply to Serena who is equal of x792 Gildarts in combat ability (basically another Laxus/Jellal or base Natsu/Gray).
Jellal was able to match and arguably surpass GS in combat ability, but was stopped by magic immunity. Once he bypassed it, he won. It suggests obvious powercreep of Jellal surpassing x792 Gildarts, and also that current Jellal would do fine against August if he can somehow bypass immunity (he can't).
August still remains King, the only Spriggan that can't be surpassed by our good guys bar Natsu, cause his ability is just that broken to mages (suzaku is a different topic all together). I see no reason why our current powerhouses can't take out any other Spriggan including Eileen. Current Laxus would beat her, so would Jellal and Erza (Gray too) if they get DS seal.