Alexandret has deep, blue-black skin, like polished stone. He has long hair, wears a crown of blossoms hewn from white quartz, and is nearly seven feet tall. He has soft hands.
His ability is unknown, but very powerful. Alexandret was able to force his ability through Silent Stone when questioning Mare, proving him stronger than both Samson and Mare. His ability is likely something physical that can cause pain. After he is killed, Mare states directly that "his ability was pain."
Mare Barrow meets Alexandret when she is being held prisoner by King Maven Calore. Alexandret is with Prince Daraeus. They want to question Mare on behalf of Prince Bracken.