Luke had chin-length, straight brown hair tied back in a ponytail and hazel eyes. He wore the typical Survey Corps uniform.
He is seen on the 57th expedition mounted from the Karanes District into the Titan-infested lands outside Wall Rose. Not long into the expedition, Luke works with Ness to take down an abnormal Titan, despite being in an open field where their vertical maneuvering equipment can not be used at full effect; Ness takes out the Titan's ankles, and Siss destroys the nape of its neck as it falls. However, almost immediately after, the mysterious Female Titan appears. Following Ness' lead again, Luke tries to strike at the Titan, but it intercepts and crushes him effortlessly, before moving on to kill Ness moments later.