You get it In the old house on Iron Island after the elite 4
Byron gives it to u
give it a metal coat and trade it
you put metal coat on scyther and trade it
Metal Coat
Trade a Scyther holding Metal Coat.
When you trade it while it is holding a metal coat.
all you have to do is get syther an give him a metal coat then trade
he probably goes back to his gym.
you evolve scyther by trading it when holding a metal coathe evolves when you trade him with a metal coat
To evolve onix you must give it a metal coat then trade it and it will evolve
the Pokemon that evolve with metal coat are steelix and scisor
A Metal Coat can be acquired outside the Iron Island cave. You can get to Iron Island by talking to the sailor in Canalave City and he'll sail you there.
You need to give ONIX a METAL COAT to hold. Then trade him and he will evolve into a STEELIX.