Question: pokemon ultra sun and moon how to get necrozma?
Answer: You can only capture Necrozma during the post-game / while climbing the Mount Lanakila toward Pokémon League. On the path to the Pokémon League, find Necrozma in a crater in a weakened state. Interact with the crater, and choose to share your Z-Ring with Necrozma to restore Necrozma's health.