I bought Pokemon Silver and got the gift code for Celebi for Ultra Sun and now that I've beaten the game and trained it up when I go to the Battle Spot and try to do a free unrated battle special's allowed it won't let me use him for a battle. I know this because I removed Pokemon from the team one by one to narrow down who it was. Now I know darn well this isn't a hacked Pokemon because it was a Mystery Gift. Really annoying considering that was one of the main reasons I got Silver in the first place. Am I missing something here like it's banned? But then why would they even give him away? Is there anyone I can get a hold of the solve this problem? Thanks in advanced!
The 3DS-Born Rule: All Pokemon used in Sun and Moon Battle Spot must be either caught, hatched, or gifted in a generation VI or VII game.
source
