Archon Quest spoilers/speculation
The powers Surtalogi and the others stole for themselves was basically the sibling's Descender powers? That's why they're no longer a Descender? The last king of Khaneni'rah tricked the sibling because they wanted to steal all the power for himself, he was defeated by the six heroes of Khaeni'rah, but then five of them (Everyone except Dain.) decided to take the powers for themselves instead? A Descender is so powerful that even that power divided in five (six?) parts is enough to make Surtalogi a galactic scourge? Just how powerful is a fully fledged Descender, then?