Question: how to transfer pokemon from black to sun?
Answer: To send pokémon from Pokémon Black to Pokémon Sun, you need to download Pokémon Bank from the Nintendo 3DS eShop, then open Pokémon Bank and go to the main menu, then tap "Download Poké Transporter". If you downloaded Pokémon Sun from the eShop, be sure to download Pokémon Bank to the same 3DS that has the game on it.