The Super Mario Bros Movie 5: Crisis on Parallel Worlds

In this alternate universe, King Bowser is good, compassionate, and understanding unlike the other one. Unlike the evil one, he wears a Ruby red cape and has a little scar over his right eye. Plus his hair is almost like a mohawk. In that world, all of the kingdoms are under the Supreme's control. An ancient being who rules that world with an iron fist. And he has many followers who obey him, only the ones who are powerful. He doesn't tolerate weakness.

The Resistance, the ones who stand up against the Supreme are Bowser, the Koopalings, Jr., Peach, Toad, DK, and Kamek.

Mario, Luigi, and Sophia however are evil in that world, loyal to the Supreme. How they ended up in the Mushroom Kingdom in their world was when their parents had Sophia marry Spike despite on him be horrible. Treating her like trash every day, she ran away with her brothers following her as they then fell into a pipe that landed them in the Kingdom. The Supreme offers them power as long as they swear, their allegiance to him. Once Sophia, Pledge her Allegiance, the first thing she did was go back and killed Spike with the Fire Flower. Mario and Luigi only followed the Supreme to keep an eye on their sister but still love being bad.

How I want the story to begin is at the Resistance base, where Iggy has discovered another world in the Multiverse where the siblings are good that they're perfect to help them. Unfortunately the 3 siblings discovered their hideout and was closing in on them. Bowser decided to be the only one who goes there to ask for help. So Kamek uses a spell that opened a portal between their worlds. Bowser then jumps in as the siblings break in.

Bowser ends up in Sophia's room, scaring her but telling her he's not gonna hurt her. But then the portal behind reopens as he then takes her away to safety. The evil siblings end up in that world where they go off and try to find Bowser to kill him, since he was the leader of the resistance