The new Spirit system coming to Super Smash Bros. Ultimate promises a more in-depth and customizable experience than any previous entry in the series. Equipping these to your favorite fighters will give them additional skills and advantages in battle. With both primary spirits to attach to the character and support spirits to attach on top of those, combatants will be able to gain immense power. You can even play minigames with the Spirits you've unlocked and beef them up even further.
But for players who have a save file for either Pokémon Let's Go! Pikachu or Eevee, they'll get a slight head start to customizing their fighters. According to a tweet from Nintendo Australia, having data for one of the games on your Switch will make a Partner Pikachu of Partner Eevee Spirit available at the start of the game.
Both Spirits will be support rather than primary but will offer different stat boosts. This isn't the first time a Smash title has featured a crossover reward. Beginning Super Smash Bros. Melee with Pikmin save data on your GameCube's memory card would've earned you a special Olimar trophy. But unlike that case, these Spirits will also be unlockable through certain in-game challenges. It's unclear how players will obtain them without the Let's Go! save data, but that's understandable given the vast amount of Spirits players will be able to unlock.
Nintendo seems to be pushing the Spirits mode as much as it can through cross promotion, as a recent update to Xenoblade Chronicles 2 gave Myrtha her Spirit costume over her less family friendly original.