Arrancar 56 Cyan Sung-Sun is one of Tier Halibel's Fraccian. In her early life, she was a snake-like Adjuchas who was a part of Halibel's team alongside Franceska Mila Rose. She was present when Emilou Apacci was introduced to them. Sometime after Halibel's audience with Baraggan, she and the others tried to help Halibel when her base was attacked by a Hammerhead Arrancar only for them to be saved by Sōsuke Aizen. Some years later, she alongside Franceska and Cyan were with Halibel when she was watching Ichigo fighting Grimmjow. When in the fake Karakura Town, Emilou, Franceska, and Cyan Sung-Sun ended up fighting Rangiku Matsumoto until Momo Hinamori arrived to help Rangiku.