Eris didn't hide the displeasure on her face, but she bowed.
(She's like a wild beast, huh...)
Reyda could sense violent emotions like that of a hungry beast, sleeping in the depths of Eris's eyes. Even if she taught a person with such emotions the defensive Water God Style, they wouldn't be able to learn it. A person like that wouldn't have knocked on the doors of the Water God Style in the first place.