Onix shows up in Wild Zone 14 during the day. This area unlocks after completing Main Mission 20. Once you’re in the zone, look for burrow holes and run over them to trigger encounters — Onix is one of the Pokémon that pop out. Be ready for Excadrill and Drilbur from these same holes; they’re aggressive and will engage when you get close.
Get a Metal Coat (side missions or late-game vendor)
Onix evolves into Steelix only when traded while holding a Metal Coat. You won’t see Metal Coats until late in the story, but there is a path to obtain one before the postgame.
- Pre‑credits option: After you reach Main Mission 35 (“Reaching Rank A”), complete Side Mission 101 (“Steadfast as Steel”). The quest giver appears on Bleu Street in the southwest part of the city (southwest of Wild Zone 16). Defeat the Rust Syndicate Grunt to receive a Metal Coat.
- Post‑credits option: Side Mission 114 (“A Feather from Skarmory”) also rewards a Metal Coat.
- Post‑credits vendor: A worker inside the Racine Construction building sells Metal Coats for 4,980 Pokédollars with unlimited stock. Racine Construction becomes a fast travel spot after the credits and sits near Gare de Lumiose, just south of Restaurant Le Nah.
| Method | When it unlocks | Where/Who | Reward/Cost | Notes |
|---|---|---|---|---|
| Side Mission 101 “Steadfast as Steel” | Main Mission 35 (pre‑credits) | Bleu Street, Rust Syndicate Grunt | Metal Coat (quest reward) | Earliest route to evolve before postgame |
| Side Mission 114 “A Feather from Skarmory” | After the credits | Near Wild Zone 17 entrance (NPC appears post-clear) | Metal Coat (quest reward) | Optional second free Metal Coat |
| Vendor at Racine Construction | After the credits | Racine Construction building | 4,980 Pokédollars | Unlimited stock for additional evolutions |
Evolve Onix into Steelix (trade while holding Metal Coat)
With an Onix and a Metal Coat in hand, put the item on Onix so it’s holding it. Start a Local or Faraway Link Trade, create or join a room using an eight‑digit code, and trade your Onix to a partner. The Metal Coat is consumed during the trade and Onix evolves immediately into Steelix. You can complete this evolution before the postgame if you’ve cleared Main Mission 35 and finished Side Mission 101.
About Mega Steelix
Steelix has a Mega Evolution in this game. You’ll need Steelixite and the ability to Mega Evolve to use it in battle later on.
That’s the full loop: unlock Wild Zone 14 and catch Onix, secure a Metal Coat via Side Mission 101 (earliest), then trade your Onix while it’s holding the item. If you plan multiple Steelix or Scizor evolutions, the Racine Construction vendor becomes a reliable, unlimited source of additional Metal Coats after the credits.
