CHARACTER/WORLD/STORY DIFFERENCES:
Out in The Reign and Typomaniac never happen. (By extension, Lavender Town doesn’t either.)
Fennekin takes the place of Chespin.
Mudkip takes the place of Fennekin.
Chespin takes the place of Mudkip.
Fennekin has never killed anyone by accident previously. However, her anger issues are still present. This manifests through undying devotion to her loved ones to a near unhealthy degree to putting them and herself in danger at times.
Chespins parents are dead. Sylveon is his adoptive father. Sylveon having known Chespin’s parents long before he was even born.
Mudkips parents are present, alive and loving.
Sylveon has associates who are fellow eeveelutions.
Pokémon are permitted to learn movesets, battling is an active sport and a career option. “Knocking out” and “Killing” are not synonymous.
Pokémon who have extra “limbs” or abilities that are not explicitly for battling, (ex. vines, fire, claws.) are fully permitted to use them in everyday situations.
All Pokémon have middle and last names to provide individuality.
All Pokemon species have different markings, fur patterns, horn shapes, hooves, paw shapes, colors, etc. This extends to Shiny forms.
Type differences in relationships are not frowned upon, most Pokémon only pay attention to whether the individuals egg groups are compatible.
Sylveon and his team run a rehabilitation center together.