To add onto this: I personally think that the no-hit achievement should be eased up a bit, seeing as a lot of the attacks are very RNG dependent and can be damn near impossible if not outright undoable depending on what controls you're using, maybe allowing up to 3 hits or disallowing healing items would work better to make the scene still a challenge to get but not unbearable.
Edit: Either one of those solutions or tweaking the attacks in general to all be purely devoid of random chance would work, it just depends on which part you'd prefer to keep I guess.