Difficulty wise because of THAT one specific attack 5 is honestly on par if not harder than Jevil for me
Also unless we're talking about a Mantle-less Knight, the Knight is probably easier than Jevil tbh. I beat them in 2 tries.
which is the specific attack?
I think the only part of the fight that caught me off-guard was
the very last attack where you have to move in the dating sim section through a maze-like section, but I still managed to survive that attack in one go, and cleared the fight in my second attempt
I had the Mantle against the Knight, but it took me like an hour to beat him
edit: some reasoning behind my ratings
3: obviously, even with the Mantle it took me an hour
2 (side b): you don't have the mannequin nor the frayed bowtie, plus kris takes all the punishment and has to do everything by himself, it took me half an hour to beat him; I assume in side a he may be the easiest
1: took me four attempts, you have the least amount of resources here
5: took me two attempts, generally easy until the very last part caught me off-guard, I didn't have protection against its element but it should balance out anyways in comparison to 4
4: took me two attempts, mantle pretty much makes the fight super easy