Ok so how about this. Roman continues this tribal chief storyline. Destroying all that is Samoan. Bringing in all the Samoans from the past and present. Now nearing the Rumble we start building to Rikishi coming back to get revenge for his kids. Roman enters the Rumble to show that there's no worthy challengers for him. Comes in at 20 and throws out everyone until he's the only one left. 30 hits. Rikishi comes out. Stops looks back. Rock's music hits and Rock is 30. Rock eliminates Roman setting up Roman going over at WM. This definitely would be way better with a crowd though.
It would also require Rock to be able to work another match and get around the hundreds of millions of dollars in insurance that the studios have invested in him. But it ain't gonna happen, sorry. That Cena match is gonna be the last one he's ever in.