Robert "Ryuusei" Twain Cartwight is the primary antagonist in the The Devourer Saga alongside The'Galin and Diviara. He was once evil beyond imagining until his death and subsequent resurrection. He first appeared in session XIV of the Epic on Caelestia. He was the seekers arch-foe. He is also father of Gaiden Cartwright and the creator of Absolix.
Ryuusei looks Asian and appears tall and slender with boney, narrow fingers although he is extremely well muscled in the torso and legs. He wears a red suit and carried a golden dragon head topped cane.
Ryuusei Cartwright has the ability to use the Cold very well, being the only one one shown in battle besides The'Galin to use three cold strikes in quick succession. Unlike Diviara, Cartwright had no qualms about using the Cold for his own amusement and even threatened it on his own servants. Cartwright also has the ability to turn his arm into The'Galin's shadowy claw or call upon the power of Omega himself. After Cartwright's resurrection, he still has this power but with less power than before.
- He was called by Xilar a "xenophobic racist and a very evil man" completely ignorant of the purpose of The'Galin and The Network, due to him not understanding the true purpose of the Devourer, and because Ryuusei showed little respect the other races excepting the vesperians. When he was revived, Ryuusei showed no disrespect to the other races, even allowing Minister Bree'Ha call him human.
- He was called "the man in Sandy Claws suit" by Dewlok.