The cinematic was pretty good. Seeing 2 powerhouses go at it, but in the end, cunning and planning decided the fight. Sylvannas went in with a plan and executed it. Bolvar just tried to use Brute force and relied on his power.
Bolvar lost when he under estimated her and thought Remorseless Winter would be enough to hide him from one of the world’s greatest Ranger Generals so he could land a blow.
Great fight. Great reversal of expectations when she breaks the crown too instead of becoming Lich Queen.