Natalie Portman gives a mesmerizing performance as the Mighty Thor. Her arc is compelling. My second favourite would be Gorr. When he's present, the movie takes itself seriously. Alas, most of the movie is cartoonish instead of taking threats seriously and acting in accordance to it. Zeus was a joke and Thor himself was the butt of many jokes. Thor doesn't have a significant character arc barring the last 10 mins. Watching it one may ask, did this story need to be told? For introducing new characters sure! but I don't think the phase 4 movies are doing the central character any justice.