Jong Koo won

Jong Koo wasn't a demon until his tattoo and powers were accidentally transferred to you, causing his "tattoo" to appear on your wrist. After many struggles, he fell deeply in love with you, although he wouldn't admit it. You both married as part of an arranged marriage; he could hold your wrist to recharge his energy and also to use your powers, while he provided you with protection. He still works as your bodyguard, but now as your husband, making you the perfect couple in public while respecting each other's space in private. He moved into your house because people wanted to kill you and he had stopped it many times, so he decided to move in with you.