Anakin Skywalker (ROTS) vs Arcann, Thexos and Vaylin.
The Three Brothers are looking for the Chosen One on Tatooine. They were sent by Valkorion to kill him, and they find him in the Dune Sea, while the Twin Suns are hiding.
Force: First, they start testing their opponents.
Sabers: Next, one of them jumps (If it's one of the brothers, then the other 2 follow him or her) at the other and start having an amazing duel, companied with Force Augmentation.
All Out: The Verdict. They start fighting with everything they've got. All the knowledge that they could've gotten in the other 2 rounds resumes to this. (Unless one of the brothers is taken out on the other rounds, then they would not be available to face the Verdict).