I feel like the last judge is a perfect test of your abilities for the 1st act
I personally found Widow fairly hard until I managed to calm down and read her better.
Widow's music and the sheer spectacle of her bell attacks really made her more of a challenge than she actually was.
Judge, it was almost more of an endurance fight where you had to keep up or get steamrolled. Harder, but didn't quite make the same impression that Widow did.