Question: how to evolve eevee into flareon ultra sun?
Answer: In order to evolve an Eevee into a Flareon, you will need to use a fire stone on your Eevee. You can find a fire stone in Diglett's Tunnel on Akala Island. Dig it up with your pokémon at Isle Aphun on Poké Pelago, or purchase it from the shop at Konikoni City on Akala Island for ₽3,000.