Advent Child

Floating island neutral kingdom? Cliched, yes, but always useful for exposition.

Fair enough. So it becomes almost like a rite of passage.

Yeah, but magic to modify their bodies, while a perfectly sound idea, implies that it's also a complete necessity for everyone to rely on the magic users. The idea for evolution was provided so that the people incapable of using magic, the warrior class and such, would be able to throw down without having to entirely rely on mages.Pushing past that, the idea of magic speeding up evolution to tens of thousands of years isn't too farfetched in the grand scheme of applying magic to reality.

No one said it had to be a quick process. Ergas as a people could have been surviving and fighting for generations prior to this point in the RPG. And with magic being a core factor of how Ergas works, it could alter the entire theory behind the normal course of evolution.

Alternative suggestions: Maybe due to the Ergas' constant need to struggle with monsters, perhaps they've become far more physically evolved. Capable of feats most humans would consider ridiculous at this point. Dodging or deflecting bullets with melee weaponry and such. Needing something of extreme force to be able to break or cripple them. Casting magic spells in seconds, though not necessarily of a particularly high power level.Maybe one of the reasons monsters stay away from Technos is because there's some sort of wave emission tool being used that drives them off, as opposed to extremely powerful weaponry. Or maybe the monsters don't try too hard because there's an outer ring surrounding the city filled with nothing but machinery, and the monsters aren't intelligent enough to figure out if they drive deeper, they'll find completely defenseless food. They just get discouraged, and attack elsewhere.

Definitely number 2, the Spike Trike.