You will have to follow special requirements if you want to evolve certain Pokémon into Pokémon Brilliant Diamond and Brilliant Pearl. For those looking for a Sudowoodo, the only way to acquire it is to level up and evolve a Bonsly. Here's what you need to know about a Bonsly's evolution in Sudowoodo into Pokémon Brilliant Diamond and Brilliant Pearl.
You don't need a particular item or level up with Bonsly to evolve it. Instead, it all comes down to making sure he can learn the move, imitate. If he doesn't know the Mimic move, Bonsly won't be able to evolve into Sudowoodo.
You can teach Bonsly the Mimic move at level 16. After she has mastered the move, all you have to do at that point is level up one more time. When she reaches that level, Bonsly evolves into Sudowoodo. However, if you have a Bonsly who is past level 16 and does not know Mimic, you will need to take him to the Move Tutor in Pastoria City. He can repeat Bonsly's moves that he has forgotten how to use. Move Teacher requires a Scale of the Heart for each move taught to a Pokémon.
When you are ready to breed Bonsly, you will need to use a Rock Incense on a Sudowoodo with another Sudowoodo or a Ditto.