Is there any clarification from the publisher/author of Hunter x Hunter regarding the quality of chapters 335 to 338?
(expansion to my comment above, which would have been an answer if I could have found the image below)
I said:


  Are your images from the weekly manga or the compendium volumes? When time pressure hits, Togashi's art will tend to suffer, as he does what he can to make delivery of his weekly art. But when the HxH volume is published, he tends to clean it up so that it looks a lot more like his usual artwork.  – RichF 5 hours ago


I can't identify the page, chapter, or volume, but here is an example image I built to answer a completely unrelated question (What defines the art-style of Japanese manga?):



On the left is Togashi's original page as it appeared in its weekly form.  On the right is his final version of the page which appeared in the associated volume.

Based on Gagantous' reply to my comment, apparently Togashi didn't always clean up sloppy weekly pages for the follow-up volume.  Maybe for the volume used in the Question to show us examples, Togashi's health (and/or deadline pressure) didn't allow for the cleanup.