Thymia (サイミア) taken from the Greek Θυμία ("spiritedness"), is a power used by certain people in the manga Children of the Whales. Users of thymia, the Marked, are able to use some kind of psychic power to move objects. It cannot be directly used on human beings, but it can give people the ability to do things that would normally be beyond their strength, like children firing a bow. It is physically exerting to use, with using thymia to move a sand boat said to be about as physically exerting as running at a full sprint. When thymia is being used, an aura appears on the user's body and the object being moved. The colors and patterns of the aura vary by person.
Thymia can only be used by those that live under a Nous.
Both Ouni and Shuan have shown an ability to change the color of their aura, and both Ouni and Miden have shown an ability to contain part or all of their aura.