@ReaverAeon , maturity and evolution are unrelated in this setting. Fran's parents grew up and gave birth to Fran without ever evolving. Which seems to be the norm in the setting - evolved beastmen are moderately rare and respected.
@Vasqueztion - it's weirder than that. All the beastmen who mess with Fran are a single tribe - "blue catkin". Which are quite similar to Fran's own "black catkin", but comprised mostly of assholes and slavers. At some point reading the novel made me think it was somehow their racial trait, and if a blue catkin stops being an asshole he evolves into black catkin or some other cooler race. The author (much later) explains why that happened, but with the way manga is going, I would not expect it for a year at least.
@ConstantErasing , Death Mage is notable in that the MC evolves not so much into a god, as an lovecraft-style "elder god" that causes people to go mad from seeing his true shape. While somehow remaining positive and benevolent. Yeah, doesn't get much edgier. You'll probably like that if you liked Kumo desu ga.
Also its manapunk setting where people base economy on farming dungeons.
But mostly, it's just unusually well-written. Politics, religion, economics, clever people, stupid people, pragmatic people and principled people - the world(s) are full of varied and interesting things.