[Master]

i have 5 eevee's

[Sman545]

I'm quite sure you will not be able to get Sylveon in PokéMMO. Also you may not get many of them if you are in FireRed. :P

[Beasty]

Leafeon and Glaceon are impossible because there is no ice/moss rock in FireRed, and Sylveon is Gen VI only.

[Master]

what do i use the master ball for

[Beasty]

Dont use it. If they ever implement legendaries you will need it at that point. Though Ive seen people RA a rare shiny and say fuck it and use the masterball there too.