Deimne is a caring and responsible individual who loves his younger sister Muirne to a fault. He expresses shock upon first learning that Muirne is fighting alongside Seliph's forces, but quickly trusts in her ability so long as she promises to stay safe. Due to not being of holy descent, however, he has a somewhat depressive personality and suffers from a lack of self-esteem, tending to see himself in the wrong light and believing himself to be inferior to the rest of the army as a result.
