10 Postgame Challenges In Pokémon Sun And Moon
9. Catch Necrozma
Completing all of the UB missions will set the terrifying legendary Pokémon Necrozma loose on the world. You can find it and catch it in the Farthest Hollow of Ten Carat Hill on Melemele Island. However, you must remember to go and talk to Looker beforehand otherwise it won’t spawn.
Be warned, Necrozma is at level 75 and by far the hardest Pokémon to capture in-game, so it’s a good idea to use your Master Ball or bring a boat-load of Ultra Balls and a Pokémon that knows False Swipe.
Pro Tip: Necrozma is a Pokémon not a UB, so Beast Balls will not be particularly useful.