Cup Knight is a demon in the series.
The Knight of Cups, or Cup Knight, is based on the tarot cards from the minor arcana, Suit of Cups. It represents change and new excitements, especially those of a romantic nature. It can also mean invitations, opportunities, and offers. They are a person who brings ideas, opportunities and offers. Constantly bored and in constant need of stimulation, but also artistic and refined. Knight of Cups represents a person who is amiable, intelligent, and full of high principles, but a dreamer who can be easily persuaded or discouraged.
The Suit of Cups indicate that thinking with the heart rather than the head, and thus reflect spontaneous responses and habitual reactions to situations. Cups are also linked to creativity, romanticism, fantasy and imagination. The negative aspects include being overly emotional or completely disengaged and dispassionate, having unrealistic expectations and fantasizing about what could be. There may be repressed emotions, an inability to truly express oneself and a lack of creativity.
Kyūyaku Megami Tensei
Megami Tensei II