A: The final evolutions of the three starters (Mozzamazel, Marleyzard, Venowatt) require you to have beaten the Elite Four once. They evolve at Lv. 99 in post-game.
In the spreadsheet, some Pokémon have the note next to their evolution. This means the evolution method exists in the game’s code, but the Pokémon is restricted from evolving in the main story (usually for challenge modes or postgame). Example: Lizakbar does not evolve into Afrobull until you beat the Champion. pokemon clover evolution guide link
However, one question plagues both new and veteran trainers: How do I evolve my Clovermon? A: The final evolutions of the three starters