The best official way to play Pokémon Crystal because the save battery won't die and you can now transfer to a 3DS game for free, also restored Celebi and wireless battling :
Celebi-Download — Pokémon Ultrasonne und Ultramond — Editionen — Spiele — Bisafans.de
Pokemon Gold and Silver 3DS (VC): How to get CELEBI using the Coin Case Glitch - YouTube
Wrangle Rare Pokémon in Pokémon Crystal | Pokemon.com
Here's How To Get Your Free Celebi In Pokemon Sun And Moon - GameSpot
Guide: How to catch Celebi in the 3DS version of Pokémon Crystal
Pokémon Crystal 3DS Virtual Console: How To Get Celebi
Serebii.net on Twitter: "Serebii Reminder: The Celebi Generation VII distribution, for buying Pokémon Gold or Silver off the Nintendo 3DS eShop, is due to end on Friday. Full details @ https://t.co/gDbXkHSvkT https://t.co/NtYo69oU9F" /
Pokemon Silberne Edition ikl. Celebi in Köln - Ehrenfeld | Nintendo Spiele gebraucht kaufen | eBay Kleinanzeigen ist jetzt Kleinanzeigen
Closer look at Pokémon Crystal download card, special edition package, Celebi and more | Pokémon Blog
Pokemon Crystal Coming To Nintendo 3DS eShop On January 26th - My Nintendo News