Mario, Sonic, and Luigi are hanging out when they meet Vivian, who shares that she’s heard about the heroes from the news. As the group converses, Vivian spots Kirby and, charmed by his cuteness, gives him a hug. This moment of warmth doesn’t sit well with Bowser, who’s furious that Vivian is now an ally of Mario and the heroes.
In a fit of rage, Bowser commands Kamek to kidnap Vivian and transform her into an Evil Shadowy Figure. Kamek carries out the plan, capturing Vivian as she hugs Kirby, and takes both to Bowser's castle. Despite Vivian’s desperate pleas, Kamek casts a dark spell, turning her into the Shadowy Figure.
The Shadowy Figure then possesses Kirby, turning him evil. That night, Evil Kirby embarks on a terrifying rampage, killing countless people in Dreamland and the Mushroom Kingdom. Tragically, Evil Kirby kills Bandana Dee. When the possession ends, Kirby is devastated, mourning the loss of his friend as he stands at Bandana Dee’s grave in the rain.
Sonic, having noticed Kirby’s grief, deciding to help Kirby. Kirby shows Sonic a video on his cellphone, revealing the truth about the Shadowy Figure. The two head to Haltmann’s office, where they discuss the threat. Haltmann decides to broadcast the news of the Shadowy Figure, sending the world into panic.
The next day, Sonic speaks with Tails, who reveals alarming details: the Shadowy Figure has killed in several places in different universes—including the Mushroom Kingdom, Dreamland, Angle Island, Undertale Underground, Bikini Bottom, and even the Dragon Ball Universe. However, Tails also shares crucial information about the Shadowy Figure’s weaknesses.
