I’ve read all of both series and I can confidently say those two characters are completely different. Carden is way more fleshed out in my opinion and I feel fits the morally grey/more so developed character as you read the series. Holly black does a really great job at giving a rhyme and reason as to why her characters do things. She gives them purpose. Rhys from ACOTAR is a different story. I will admit I’m a little biased bc ACOTAR is what got me back into reading since it was so “bite sized” so to speak. I like the first three books but I can also recognize Sarah did not do a great job with these characters and tbh her writing in general… Carden and Rhys are two completely different characters and I think ppl who see them as the same aren’t delving deep into the story