Characters from Sakuna: Of Rice and Ruin will appear in Super Smash Bros. Ultimate as Spirits. A total of three Spirits will be available starting on July 16, 2021. The “Rice is Power!” event will last for five days and allow players to obtain Sakuna: Of Rice and Ruin Spirits in Super Smash Bros. Ultimate. [Thanks, ryokutya2089!]
Details regarding the event itself have yet to be revealed. Sakuna, the main character from the game, will appear as a Spirit players can obtain. Additionally, the two other characters shown in the teaser artwork include Tama and Princess Kokorowa. You can check out the teaser below.
— 大乱闘スマッシュブラザーズ【スマブラ公式】 (@SmashBrosJP) July 14, 2021
Super Smash Bros. Ultimate has seen a plethora of characters added into the game as Spirits. In June 2021, players could obtain the Razewing Ratha from Monster Hunter Stories 2: Wings of Ruin. However, this Spirit could only be obtained by having save data from Monster Hunter Stories 2 on your console. In April 2021, Super Smash Bros. Ultimate saw the addition of Monster Hunter Rise Spirits. This included the flagship monster for this entry in the series, the Magnamalo.
The Sakuna: Of Rice and Ruin OST is currently available to purchase through Steam. This includes a total of 42 tracks from the game. The OST was originally exclusive to the digital deluxe edition of the game.
Super Smash Bros. Ultimate is immediately available for the Nintendo Switch.