Heartlight

A Heartlight was a light on a being's chest that glowed while they were alive. When the heartlight glowed brighter for a split second, the heart beat. A being's heartlight started blinking when they were dying, and it went out when they were dead, as shown in Turaga Lhikan's death. Heartlights appeared on Matoran, Toa, Turaga, and other species in the Matoran Universe.