What is how to evolve yanma?

To evolve Yanma, you need to level it up while it knows the move Ancient Power.

Here's how to ensure your Yanma evolves:

1. Teach Yanma Ancient Power: If your Yanma doesn't already know Ancient Power, you'll need to teach it. This can be done by leveling it up to a certain level where it learns the move naturally (check the specific game's data for the level). Alternatively, in some games, you can use a Move Reminder to re-learn the move if Yanma has forgotten it. Move Reminder locations vary depending on the specific Pokemon game.

2. Level Up: Once Yanma knows Ancient Power, simply level it up once. It will evolve into Yanmega immediately after the level up animation if the evolution condition is met.