I mean, everything about the fight. Taking on an entire army of the scourge and Bolvar single handed, having the strength to physically throw around hundreds of tons of Saronite, having those magical chains come out of nowhere with no explanation or reason she just has that technique now.
Everything about that cinematic, aside from the visuals looking good, was good.
Like I said, I made a pretty lengthy post on how it could have been done so much better and more in line with here character.
I don’t take issue with her beating Bolvar, what I take issue with as that the hyper intelligent tactical character that worked best by using others and using tools to her advantage was basically turned into Frieza from Dragon Ball Z. Instead of utilizing her remaining loyal Dark Rangers and Nathanos, instead of having pulled out a magical artifact like maybe a repaired lantern from Legion (the one greymane smashed), instead of any of the things that actually made Sylvanas a dangerous character to deal with she fights Bolvar and an entire army of scourge head on without so much as a scratch.
That, is what I take issue with. I would have been fine with her beating Bolvar, but the way she did it… no, a million times no. Its bad writing from start to finish and the most frustrating part is that it could have been really good.