What's this about a scrapped Spirit Battle?
I guess with Wario being her choice, it makes sense since he is her main motivation and they have vehicle moves.
Shame it was removed, but at least her Spirit is in the game at all.
Yeah, it turns out that just about EVERY collectible Spirit (in the base game version of Smash Ultimate) was going to have a Spirit Battle. So Enhanceable Spirits (i.e. Bandana Waddle Dee, Devilish Dr. Kawashima, Angry 5-Volt), Summonable Sprits (i.e. Mona, Jimmy T., DJ Octavio), and Purchasable Spirits (Kururin and his Helirin, Beetle from Excitebots) could all be fought on the Sprit Board (most likely after they were acquired at least once).
This being said, Mona's Spirit Battle would have involved her soul possessing a puppet clone of Wario (in his red biker outfit) of all people. In you didn't see it earlier, this was what I meant in an earlier post about how it was neat to see Smash Ultimate's dev team have things come full-circle with WarioWare Gold having Mona mention how she admires Wario's fashion sense, and now she could actually fight in his body (in a sense).
As
PsychoJosh
has said, Mona would have had the Wario puppet she was possessing spam the usage of the latter's motorcycle, and just about all aspects of the move would have been buffed up (Such as increased speed and attack power). Only thing I find a bit odd is that the battle would have taken place on Omega-form Mario Bros. Considering WarioWare's primary setting, I kind of thought the battle would taken place in New Donk City or something.