Whip/Story

According to the 2001 novel written by Akihiko Ureshino, Whip is a clone of the real Seirah; Seirah was K's biological older sister who died after being abducted by NESTS. Ureshino comments that he wrote this origin story for her because the developers didn't want to clarify anything about her to him. Until this was written, Seirah is only shown briefly as a child in K's memories, imploring her younger brother (K') to remain strong until they meet again.

Regardless of whether she is a clone or not, she is called Seirah by people who knew her in NESTS. She also responds to the nicknames Sally or Sarah. Due to NESTS experimentation on her body, she's able to manipulate her specialized whip with ease. She befriended Krizalid under the assumption that he was her brother before she escaped from the cartel. She used Sally as a codename to join the military.

She is eventually assigned to Heidern's mercenary unit under her current name, Whip. She enters the King of Fighters tournament to investigate NESTS. While her team isn't present, she privately interrogates NESTS agents to find information regarding herself and the whereabouts of her brother.

After learning a startling but undisclosed revelation from Zero, she joins K' and his objective to destroy NESTS. After NESTS's downfall, she returns to her duties under Heidern's command. During the KOF XI tournament, she serves as backup for the Ikari team and asked Kula Diamond to enter the tournament with K' and Maxima.