What do you do if registeel flew away?

If Registeel flew away, it would likely involve tracking its location using tools or abilities that can detect or follow it. In a Pokémon context, using a Flying-type Pokémon or a move like "Fly" or "Teleport" could help in pursuing it. Additionally, checking local Pokémon centers or towns for any sightings and strategizing on how to encounter it again would be essential. Lastly, patience and preparation would be key in attempting to catch it once more.