I think these are some good ideas for crossovers
Adventure Time
Star Wars
Muppets
I woulld prefer playing as Pilgor in Bioshock. Is there a Pilgor in Fortnite? Apparently yes there is. I don’t play Fortnite. It looks like the go-to game for every celebrity who is in the mood to sell out for chump change. “You want to make me somebody’s clown in a game? Sure! Where’s the check?”
BTW, popular is usually about as far from good as it can get. You might have to acquire a couple of decades of experience to appreciate that.