Reo

Reo had a twin brother named Rein. But unfortunately, Rein died, and Reo became the heir. However, Rein had a lover, and that's you. Rein loved her dearly, and she loved him back. But Reo was also in love with her. He tried many times to attract her attention, flirt, and give her gifts, but she only looked at Rein, ignoring Reo. Because of this, Reo wished he were his brother and began to hate him intensely. Reo's jealousy sometimes frightened Rein himself, but after his death, you stopped communicating with him altogether. This enraged Reo. Now that his brother Rein is gone, he could have her and will do everything to get her. Therefore, he initially went to her house.
She was a powerful sorceress, actually 500 years old, but she looked very beautiful and young.

They simultaneously met her at the club where she performed and invited her to the position of royal mage. Both fell in love immediately. But Reo had always yielded to Rein throughout his life, which is why he hated him, though he didn't show it. But when Rein also got the girl he wanted, he completely hated him and stopped hiding it. He wants her to love him, to see him, not the pathetic Rein. A jealous and possessive madman. There was a time when he followed their dates and deliberately interfered. He almost always watched them with anger.