Cain is particularly interested in Gyeong and takes to trying to make him feel better when he appears upset.
To that end he kept Gyeong safe out of convenience where he told him to go and sit still with his head down and Cain will come and get him soon. Initially Cain wanted Gyeong kept alive as a means to reach the human world. Cain can also use his wings to fly and carry Gyeong as well. He is extremely agile and can form sharp claws to slice apart foes.
His physical strength is retained as a human where Cain can effortlessly break free of cuffs. Cain states his skill is on an entirely different level than that of a low class succubi. This was Cain forcing the 'door' open to go in and his eyes gleam yellow as this is carried out and consequently a serious physical injury through his chest is healed. Making eye contact with a human can induce a feeling that everything inside one's body is seeping out and filling up someone else. Cain could also diminish the fire around them by raising his hand to cause it to implode into nothingness. Cain first demonstrated his prowess by rescuing Gyeong from smoke inhalation by making contact between each other's mouths. Possessing magical based powers, these are able to be restored but they deplete faster in the human realm. Fearless in combat, it is the case that Cain appears to enjoy fighting savagely. Sensing other monsters before they arrive, Cain sees them and feels both relived and disgusted. Cain feels Gyeong has a big responsibility to alleviate this by taking him sightseeing to buying him some good food. Even if they are different species, Cain gets one thing straight, that it is because Gyeong is being stubborn and will not let him go back to hell that is the reason he is here, all bored. Feeling it would be good to have a name that can be pronounced by the human tongue, Cain gives his name as Mr. Smiling at lot at Gyeong, Cain says since he is kind he shall tell him his name again. Cain assures Gyeong he has a team trying to decode the symbol that Gyeong showed him before and that he will defeat a lot of demons if they are here then save as many humans as he can as he lists of things to help Gyeong feel better. When hurt Cain seeks out Gyeong to replenish his powers and empathizes with him by assuring him that there is nothing to worry about. He also retains his pronounced sharp teeth and tanned complexion. Cain has long white hair in this appearance and keeps the color when as a human. His fingers are clawed and his left forearm is black and the right one white. This form has a very long tail, and black shadow like bindings around his legs. His demon form features four large black wings out from his back with the upper two bat like with a white tinge to them and the lower two similar yet longer and thinner. Cain's magic did not disappear due to the fragment of the angel. He is familiar with crow like demons and that they serve Satan. The name of the devil has a magical effect on humans so whilst he speaks it, Gyeong is unable to hear it. Cain gave Sid a new life with his magic and gained a pledge of loyalty from him as a second-in-command and overseer of Cain's territory. It has been a long time since he took on a human form and he remarks how a lot of things have changed from 3,000 years ago. He was transporting weapons from heaven where Cain survived being pierced through the heart. Living in a twenty first century setting, he is aware of Satan who Cain considers a cheapskate.