I think that's the author's intentions. It became obvious since the name Go Yahwi rhymed with Goyangi which means 'cat' in Korean (I remember someone mentioned this in the story too). Even his irises are those of cat's. While Cain's full name from his ID is Canis Lupus which is a scientific name for wolves. And as we can see, Cain was the reincarnation of Jooin's dog from the past life.
At the moment I want to see more developments from Cain's side some more.
You're right, that's the author's intention, to depict Yahwi as a cat and Cain as a dog, but I really think the way the author does it is so well done. I just wanted to point that out .
All relationship drama aside, am I the only one who finds it incredibly cute how Yahwi and Cain make such a good match with their animal beings in terms of character?!
Yahwi is so cool, aloof, elusive, doing his own (unfathomable) thing like a cat, yet is devoted to Jooin in a very intimate way and has his sweet moments when the two are alone.
Cain on the other hand is really like a big clumsy Golden Retriver, he shows his affection towards Jooin so openly and honestly and would probably do anything for him. He's not as twisted as Yahwi, but easy to figure out and simple and straightforward to deal with.
So, the big question is: Is Jooin a cat person or a dog person? Which animal does he like more?