Ludwig (your second example) is, I think, a perfect example of this. He's one of the most disgusting designs they've ever made, and yet when he stands during his second phase, and the music swells, you get an immense feeling of the grandeur and power of Ludwig before his fall to the disgusting creature he became:
https://youtu.be/7n1qe2ZSTPA?t=102
That being said, I think FromSoft's designs sometimes ARE "just gross". But it's an admirable guiding principle, even if they don't always hit it.
[0] https://vignette.wikia.nocookie.net/dragons/images/a/ac/OtTP...
[1] https://static.wikia.nocookie.net/darksouls/images/4/49/Ceas...
if you want to see pure grossness like they try to avoid watch something like peter jackson's "dead alive" the souls really nail a kind of tragic or even self respecting aspect of deformation in their more "offputting" characters.
[0] is the Asylum Demon, which is literally the first boss in Dark Souls.
Bloodborne cranks the gross-out factor up to 11 with [1] and [2].
[0] https://i.ytimg.com/vi/6qCB_x7KQR8/maxresdefault.jpg
[1] https://bloodborne.wiki.fextralife.com/file/Bloodborne/ludwi...
[2] https://1.bp.blogspot.com/-kXCskueejFY/XLlAKLB-nmI/AAAAAAAAd...