Here's why:
* Arceus is a powerful and central figure in the Pokémon universe. Giving it away as a Mystery Gift would diminish its significance and rarity.
* Arceus is often the final challenge in a game. It's designed to be earned through hard work and skill, not given away easily.
* Arceus has been distributed in special events and promotions. While not Mystery Gifts in the typical sense, players could receive Arceus by attending specific events or by purchasing special editions of games.
However, there have been instances where Arceus was distributed as a Mystery Gift in specific circumstances:
* Pokémon Black and White 2: Players who had a save file from Pokémon Black and White on their DS could receive Arceus as a Mystery Gift.
* Other Limited Events: Occasionally, Arceus might be offered as a Mystery Gift for a limited time during a specific event.
If you are hoping to receive Arceus, it's important to stay informed about any special promotions or events that might be occurring.