The complete means 100% - it means all legit Pokémon caught, all gym badges, Elite Four finished, all side quests finished and all endgame finished.What do you mean with "complete"? League defeated? All Pokémon caught? You can set it as complete with PKHEX.
Here's my save:
I think it would take while and due to lack of legit Pokémon data, I ended up to create illegal Pokémon that I have no plan to play online, but I will fix if legit Pokémon data is available.