How do you get a leafeon on soulsliver?

Answer 1

First you get an evee from bill in goldenrod city after you beat the Pokemon league or get one at the game corner in celdon city (the one with the kanto department store) and get it for 6,666 game corner coins and trade a Pokemon holding a moss rock from Pokemon diamond/pearl/platinum and use it on evee. Or you can trade the evee into diamond/pearl/platinum and use a moss rock on evee and trade it back (if you want to) or go to eterna forest where you can find a rock with moss on it, you walk up to it and press A. This must be done in the day and the evee must like you a whole lot. You could also use a leaf stone.

I am not to sure about the last way to evolve it so if it doesn't work just try the other ones.