Darth Chosis was a female Mirialan Darth Lord of the Sith under the Rule of Two. She was the apprentice of Darth Ramage, and participated in her master's study of time. Rejecting the possibility of time travel, unlike Ramage, she instead sought abilities similar to Aing-Tii flow-walking, projecting her consciousness into the past or future to witness or manipulate events. Considered overly philosophical and metaphysical by her scientific master, Chosis was dismissed as a threat, and thus Ramage did not foresee his death at her hands until it became reality.