Love and obsession.
This feeling of posession encircling his gut hasn't left since the first day he saw her and now he is seeing her again with this boyish man with the tiny muscles who is not even worthy of a strand from her hair.
She seems happy with the man but he knows better and he is so hell bent on protecting her from a foreseeable heartbreak she might suffer from someone who doesn't deserve her. She laughed at something he said and this got him angry that he wanted to hit her so hard for being so naive "you have to be strong to have better choices" he almost screamed that out and so he calmed himself thinking one day he will have to save her from this man and which he should do sooner than later.
He looked at her again, her honey coloured hair brings out something soft in him and also the way she smiles always make him think of a freshly brewed morning coffee, her tiny fragile figure makes him think he is some kind of a goddesses calling her Aphrodite wouldn't do her justice, all these qualities made him realise that he loves her but she could have loved him too if not for the tiny muscled man.
Days turn into weeks and he has summoned enough courage to 'save her', he kidnapped the both of them and put them in a cellar where he told her for the first time that he loves her, the look of confusion on her eyes and the way she was crying for help made him so furious that he had no choice but to send the one who made her feel like this towards him to the domain of Hades. She made a high- pitched cry like that of the canary before his bullet pierced through her heart like Cupid's arrow, he looked at her lifeless body and said "if I can't have you honey, no one else will"