A holographic lifeform on the Gamma Quadrant planet Yadera II who was not aware he was a hologram. Colyus was the Protector of his village and was investigating the disappearance of 22 villagers in 2370 when Jadzia Dax and Odo arrived to examine an unusual particle field. Colyus arrested the two visitors, but they convinced him they were not responsible and would help him find the missing persons. Dax and Odo discovered that all the villagers, except for one, were holographic projections, and the disappearances were caused by a malfunction in the hologenerator. Colyus convinced his people that if they were to survive, they must allow Dax and Odo to take them off-line temporarily and repair the reactor before it experiences a complete failure. They agree, and the Yaderan society was restored to its original state.