Flight.

The demon is very lucky to get into contact with something like that. He had been previously unheard of, but he suddenly became known. She too will have her life changed once she gets her hand on it.

She believes that the weird demon must have come across the spatial artifact and also gotten access to the chaos energy through it. 

The other option is that the weird demon is a weakened demon king and that the spatial artifact belongs to him in the first place. It will also explain why he is so strong for his rank. But that will only make her want him and the spatial artifact more. Eating him should grant her his authority.