However, you can get an Umbreon in Crystal by:
* Trading: You can trade an Espeon or a Eevee from Gold or Silver into Crystal. Then, evolve the Eevee into Umbreon by leveling it up at night.
* Using a Game Shark or Action Replay: These devices allow you to cheat and insert Umbreon into your game, but this is considered unethical by many players.
* Using an emulator and save file: You can download a save file with an Umbreon from the internet and use it on an emulator. However, this may be considered cheating or piracy.
To evolve Eevee into Umbreon:
1. Have an Eevee in your party.
2. Level up your Eevee between 5:00 PM and 4:59 AM in-game time.
3. Make sure the Eevee has a high enough friendship level. You can increase friendship by using vitamins, petting it, and letting it walk in front of you.
Remember, you can't get Umbreon naturally in Pokémon Crystal. You need to use external methods to obtain it.