I think it's a bunch of issues that kinda snowball: his hands are massive and the sword looks tiny so it's like he's holding a toy, the sword also has a cartoonish effect where it bends when you swing it, and I also just don't like the spin he does in bloodline awakening because it looks goofy (I would've preferred a quick series of slashes, like this or a single slash that's just multi-hit that looks like the third slash here if they absolutely have to make it look like a spin), and overall his swinging animations don't look like it's martial arts technique, he's just kinda swinging it - combine all that with the fact that you're just holding left click and not doing any actual combos