I HAD A CHAOS DARK CHAO IN SA2B. I MOVED HIM TO SONIC ADVENTURE DX. HE VANISHED AFTER I TURNED OFF THE GC. IS THERE ANYWAY I CAN GET HIM BACK?
Make sure to ALWAYS save by either exiting the Gardens by choosing "Quit" in the pause menu, or exit the actual Garden... so, no. Sorry.

~ SA Tails