i got shadow in the veldt cave but i can't seem to find relm. Does getting shadow cause relm to never come back if not where can i find relm?

You're in luck. Actually, if you did find Relm in the Veldt Cave, it would mean Shadow is gone for good. It all depends on what you do at the end of the Floating Continent.

At any rate, Relm can certainly be re-acquired into your party. Try looking around the town of Jidoor...

thanks i knew about relm being there instead of shadow but then i thought does that mena relms gone if shadows there instead thanx again.