It's just because, aside for plot, lol, I think Cain genuinely trusts and likes Sid. In the raws, Cain looked like he liked and cared for Sid when they were younger. Even in the first few chapters, Cain acts like an annoying but good friend to Sid. Sid, being the ungrateful bitch he is, is taking advantage of our good boi Cain.
sid doesnt deserve cain :((
Right? I mean, Cain could have one-shotted Sid right there but no, he just threatens him and even gave him that friendly smile at the end. But nooo, Sid had to go like "Ugh, you're too kind, this underworld needs a stronger leader". Bitch tf.
for real T-T i really dont like sid’s character
okay fuck sid tho, jin yeong doesnt really deserve that, like he has an unrequited love on his best friend and sid is basically ruining his mental state. also, my baby cain was so close to figuring out that sid was the traitor and i was so ready for sid to get his ass beat but cain is so oblivious T-T my baby come on... anyways, i love the s3x scenes between cain and gyeong joon, theyre so hot and its slowly becoming more and more domestic between them and its so cute! i love the story and the art!!