OK so, my little theory is that the final Splatfest of Splatoon 3 will be Past Vs Future. With Shiver representing team past, Frye representing team future, and Big Man being on team neutral. If team past wins Splatoon 4 will be set before or during the Great Turf War 100 years ago, and if team future wins them we might get a really futuristic feel with Splatoon 4.
I just wanted to put this theory out here in case it turns out to be right. It probably won't be, but you never know. Also I've been hyper fixated on Splatoon 3 and wanted to post something about it.
