>>55533308The most grown up a history with magical partners can be is “for teenagers”, never “for adults” because no functional adult places their pets at the center of their life.
For kids (Pokémon): the magical creatures take the entire focus, everything is about them and what you do and how you relate to them
For teenagers (Digimon): the magical creatures get a lot of focus, but the humans also struggle with typical real life issues and develop meaningful relationships with other humans
For adults: magical creatures are pets, they can brighten up your day, but they will never be the center of your story or an important character. Your dog might put a smile on your face but will not really be a real support with your job, your love life, lack of purpose, depression, etc.
You either have a truly adult story, or a story with magical creatures. One will push the other out of the spotlight