Teiken, also known as Dīng Yán, serves in the newly formed anti-Wangliang Corps, established following the mysterious destruction of the previous sixth unit. He is visually marked by his green hair and habitual hat-wearing.

His personality is defined by cowardice, manifesting as a strong aversion to combat and confronting Wangliang spirits. This fear originates from traumatic experiences linked to the previous sixth anti-Wangliang unit. His resistance to missions necessitates external pressure for participation.

A defining element is his dynamic with the mascot character Aixin Chatong, a talking tea caddy, who frequently accompanies him. Aixin Chatong acts as an intermediary, often pressuring or goading Teiken into action despite his protests, providing comic relief.

His established traits—cowardice, distinctive appearance, and comedic reliance on the tea caddy—remain consistent across the documented media.