>>42719312one of my biggest beefs having grown up in the height of the whole companion monster genre boom is that even though Pokemon was really onto something with the IV/EV thing in terms of trying to create a "unique" host of pokemon, where even the stats of two of the same type of pokemon, at the same level, would still have subtly different stats influenced by gameplay. It never actually made the experience feel particular "personal."
Digimon had its own agenda with taking the whole tamagotchi model of caretaking where your action or inaction had actual consequences, even if it was super stat light as an electronic keychain toy.
And Monster Rancher took that same virtual pet format to one of its most logical extremes and just sat you down with your one partner (at a time) and really gave you that intimate experience of knowing that you were in charge of not just raising its stats and making it win fights, but determining how long it lived, how often it got sick, or how stressed out it got.
Monster Rancher and Jade Cocoon took the breeding/legacy mechanic (before Pokemon implemented it) and really gave it a satisfying sense of progress. You didn't just take your old monster and make an identical copy but with bigger numbers, you could pass passive features as well as combat skills, and visual traits from one generation to the next.
And Shin Megami Tensei actually addressed the implications of its own monster catching mechanics and settings throughout a lot of its games and spinoffs. (The first Jade Cocoon did a little bit too, and that was a lot of fun.)
