This is Tenebris. He's Akina's husband. He's not the father of all her children. He's Rose's father. They didn't marry right away, they actually had a falling out due to an affair they both had. They weren't mad at each other, they couldn't because they were both cheating at the same time. Akina cheated with Aero's father. That ended really badly and Tenebris didn't exactly have the best relationship with the woman he was with. He won't tell what happened but he was not happy when he heard what had happened with Akina while she was with Aero's father and when he heard how Aero was the offering to a demon for a deal his father made, heads were ready to roll. So after Akina's abusive relationship they fell back in love, permanently.