HISTORY is on the line on Sunday! *many reasons*
If Nadal wins, he will become the greatest clay counter ever. Bjorn borg has 6, but I am sure even bjorn borg would say with 6Nadal is the best ever on clay given the competition.
moreover, he will be in double digits, (i'm not sure if djoke can put as much a fight on grass against him) so he would be really close to #11 which would bring him merely 4 slams away from 15 and arguable G.O.A.T) and would be kinda funny because everyone was wanting djok to lose, and it would only prove to be the start of another nadal run.
If Fed wins, he will have another slam, and surely be the current G.O.A.T. (won't be questioned unless Nadal reaches one less than his slam count)
Also, if Fed wins, Djoker is number 1 for the first time, and has officially accomplished a new Feat, and would upgrade his status a bit.
Doesn't matter who wins, a lot is on the line.