Brien is slightly shorter than the average for a Celt male at only 5' 9" tall yet his arms are nearly as big around as most men's legs. His hair is a dirty blonde and his eyes are blue like the ocean.

Most often he is dressed in a chain shirt with a heavy wooden shield. His head is protected by a steel cap. On his belt are a longsword and shortsword, both of exceptional quality. On his back are three exceptional javelins. A masterwork dagger is in his left boot. Also around his belt is a sling tucked in and a pouch of obviously sling bullets.