Some Spirits in Super Smash Bros. Ultimate can be evolved once they reach a certain level in the game to become more powerful versions. While all Spirits can be leveled, some can be Enhanced once they reach Level 99.
When you do enhance a Primary Spirit you will see that their level has gone back down to level 1, and their stats may be a little bit lower than before. However, depending on the Spirit you will see that there overall star rating has increase, and they’ve likely gained new abilities that they can offer you in battle. It will also not take long to make them more powerful than their previously maxed out stats for attacking and defending as their new ceiling is much higher than before.
You can Enhance Spirits in the Collection section of the Spirits Menu. You can also enhance Spirits while in World of Light mode before heading into battle. By using the level up option by pressing the L Button when looking at the Spirits section of the Party menu.
Not all Spirits can be enhanced. Look at the cards in your collection and you will see a note that says that they can be enhanced at Level 99. Once you reach 99 you will get a notification that asks you if you would like to Enhance the Spirit.
Using Spirits in Battle is a good way to level them up, but you can also feed them snacks to do it quickly. You’ll earn snacks while playing World of Light and it can be used to level up a Spirit to 99 very quickly.
If you happen to be having trouble with World of Light, leveling up your Spirits and Enhancing and evolving them could be the answer to your problems.