Seppuku is a malignant narcissist. He dwells in the shadows enticing Deseree and Narcorrow towards suicide. He is a rapist that sneaks into the bedroom in the middle of the night and takes what he wants when he wants.
Seppuku is the darkest of all emotions and he has the ability to harness darkness as a tool to drag Deseree and Narcorrow into the pit of despair. Narcorrow is the most susceptible to Seppuku because Narcorrow tends to dwell on the fringe in a toxic narcissistic fashion.