Latias is now appearing during sleep research for the first time in Pokémon Sleep, giving players a new Legendary encounter to discover through their nightly sessions. During the event, the field BGM will feature a special track from Pokémon Heroes The Movie, rearranged into a gentle and relaxing style to match the game’s tone. The crossover adds a nostalgic touch while enhancing the overall atmosphere, offering players a unique audio experience alongside the chance to study Latias.
Source: Official Pokémon Sleep news and PokemonSleep.net
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