In the past couple of days after Arad's disappearance, Doma and Tina were left in the dark. None of them could contact the mortal world or check to see what had happened. As expected, Tina panicked for a few hours, but luckily Doma was there to support her.
Doma knew several facts about Arad, even though they lost all contact thanks to a few tricks. The first trick was that she herself was still alive. On the day they met, she had placed a curse on them both. If any one of them were to die, the other would feel it. To make this curse stronger and impervious to all interference, she added a condition on her side. If Arad dies, she'll die with him, melting her soul and all of her power into a curse that would emerge from Arad's body to haunt whoever killed him.
She didn't die, so Arad was alive. It was that simple.
