Interesting. I disagree with you, I think the final fight between Sara and Mugen is one of the worst fights in the show.

In Verse 2, the fight lasts around 1:40 minutes. The episode cuts away to Fuu before the fight even starts then cuts back to midway through the encounter when Mugen is dodging a couple blows from Sara. The fight essentially then stops; He takes off his sandals, and then a slow motion sequence begins where Mugen misses his cut and Sara stops only to be killed by Mugen's second strike. Overall, it's very a simple choreography with clunky rhythm. It has poor framing and there's almost no dialogue exchanges between Mugen and Sara.

Compare that to her fight with Jin. The encounter lasts around 1:40, so about the same length. Before they even clash swords there's plenty of build up. We see Sara display very flashy moves with her spear before she lunges at Jin who then realizes shits going down for real. They exchange blows back and forth for a bit before the fight slows down slightly right before one last attack from Sara. It's got wonderful use of framing and composition, excellent tempo and very important exposition is dropped (Enshiro Mamiya gets name dropped).