After seating himself comfortably behind Stella, Serac promptly pulled up her shirt and held out his hands. Watered bubbled up from his skin, crawling over his fingers and coating his hands as he placed them on Stella's back.
It was one of the many techniques that Serac had under his command–Hydropeutic Assessment. It used the water on his hands to interact with the water inside another's body, allowing Serac to intimately view that person's physical condition with a single touch.
As soon as Serac placed his palms on Stella's back, the water was absorbed through her skin. He furrowed his brows as he scrutinized every aspect of her condition before finally breaking contact.
Creation is hard, cheer me up!