How do you evolve Onix in Black 2?

Onix

ONIX - new Evolution by Tornupto-Z on DeviantArt

Onix Pokémon: How to catch, Moves, Pokedex & More

Onix - Evolutions, Location, and Learnset

Pokemon Legends Arceus Onix

Let me ask, how do you evolve onix into steelix? help me! : r/pokecord

Pokemon Onix (61/108) 2016 XY Evolutions - MINT PSA GRADED 9

Onix and Steelix Coming to Pokemon Sleep on November 14, 2023!

Which Onix is smarter to evolve? One is higher CP, the other is a cool shiny. I know usually you always want the higher CP, but is there any collector value to

Pokémon Sword and Shield Evolution List - benefits of evolving Pokémon, how to prevent Pokémon evolution and Pokémon acquired by levelling up explained