Misty Mei functions as the primary antagonist in the second installment's narrative. A demonic entity and lieutenant to Rococo, she is driven by vengeance for Asmodeus's defeat. Misty Mei orchestrates the corruption of Rika Manabe, twisting her into a dark Devil Angel. This act forces the emergence of a new Devil Angel, Hikari Jinno, to save Rika and counter the demonic threat. Misty Mei's actions directly fuel the central conflict of this story arc.

Physically, Misty Mei possesses distinct demonic traits, including functional wings. Her design incorporates a maid uniform, gloves, stockings, a collar, and a headdress. Specific attributes include blue hair, pink eyes, and a height of 165 cm.

Her personality reflects her antagonistic purpose. She actively collaborates with Rococo to advance demonic goals, specializing in corrupting existing Devil Angels into enemies. Serving directly under Rococo, she executes plans targeting the protagonists and exploiting their vulnerabilities.

Misty Mei's narrative presence is exclusively tied to Rika Manabe's corruption and the subsequent purification efforts within the second story arc.