>>44956914I've toyed with the idea a few times myself but as an example I had things like
Baby Luigi (Normal) evolves to Luigi (Normal/Fighting) evolves to Super Luigi (Electric/Steel) or Mr. L (Dark/Steel, evolves from low Friendliness) or Dimented Luigi (???, evolves when you have Dimentio in party or holding a Strange Sprout item)
Baby Peach (Normal) evolves to Princess Toadstool (Normal) evolves to Princess Peach (Fairy) / Sporty Peach (Fairy/Fighting, if moveset at evolution includes a Fighting type move) / Shadow Queen (Dark/Fairy, if holding Suspicious Item)
Baby Bowser (Fire) evolves to Bowser (Fire/Dark) evolves to King Bowser (Dragon/Dark) / Bowletta (Dark/Ghost, if holding Suspicious Item or have Fawful in party) / Bowsette (Dark/Normal, if holding Pretty Crown)
Koopaling mon has the same movepool but the design changes based on Personality. This might include Bowser Jr, but he could be separate to evolve into Shadow Mario while holding a Bandana item.