Let me play Waluigi and Captain Syrup minigames in Warioware.
Let me meet up with the Warioware cast in a Wario Land game.
And on that note, please make a new Wario Land game. It's been 14 years since Shake it.

As an extension of this, let BOTH the Wario Land and WarioWare casts into the expanded Mario universe games.

I have yet to see a reason as to why the DK-original cast like Diddy and Funky can show up for sports, parties, and Mario Kart but Captain Syrup, Jimmy T, or Ashley can’t.