Village elder and prominent member of the population on M7G-677. The day before he turned 25 John Sheppard and his unit crashed their Puddle Jumper on this world. Keras's troops intercepted the "Full Growns" and returned them to his village.
Despite the warnings of his lieutenant, Ares, Keras took a liking to Sheppard. He confessed to the reason that no one over 25 could be found -- because those who would be had given their lives in a ritual sacrifice. This has been going on for 500 years, and they believe it keeps the Wraith from culling. Keras invited Sheppard to stand witness as he prepared for his death, but during the ceremony the Major found an active Wraith transmitter, and destroyed it with his weapon. This abruptly halted the ceremony.
Even after Sheppard informed him that a small piece of technology was the primary role in protecting their society, Keras had difficulty believing that the Wraith would not come if he did not kill himself. He encountered strong opposition from Ares and his supporters who feared that Keras may be swayed to the beliefs of the Full Growns.
Keras offered to escort the Full Growns back to their vessel, but halfway Sheppard led him to the old city, where he saw the device for himself. Ares and his men caught up with them and forced them the rest of the way. When a Wraith probe appeared in the sky' Ares believed Sheppard and his team were to blame for allowing the enemy to encroach on their territory. He shot an arrow at the Major, but Keras stood in the way to take the hit.
Soon Neleus reported to Ares, saying he saw how the probe fell from the sky when Rodney McKay activated the Z.P.M.. Keras, provided a sling from the Jumper, admitted that laws would have to be changed, and that, with the electromagnetic shield extended, there would be no more mass suicides.
Childhood's End - Keras greets Major Sheppard and his team in the treetops of his village, but he and Ares are hesitant to allow them to remain for fear that the Wraith will soon arrive to cull the villages.