Extermination is the arc where Worm changes as a whole. It goes from being about a conflict between superheroes and villians to a hopeless battle with a kaiju. Were you surprised by the tonal shift? How would you rate it compared to previous arcs?
It’s a bit of a shift, but it’s not really unprecedented or out of left field. Arc 8 has a lot in common with Arc 5 when it comes to this, and both of them tie back into a concept that was introduced all the way back in 3.6. Through this and other things, the story has been setting this Arc up for a while, which is one of the reasons why this feels like a larger subclimax, an “end of part 1” point.
As to whether I was surprised by the shift in tone… I’m not sure how much there really was one. I did know this story was pretty dark already. The bleakness did reach an all-time high in 8.3, but fortunately, it mostly went back to levels I was used to after that, although still with significantly more death than usual. That said, the aforementioned bleakness high in 8.3 did get to me, being quite a bit more than I had expected even from this story.
In retrospect, Arc 8 was a masterpiece. Though I still think Arc 4 is my favorite so far, it’s definitely one of the better ones.