Nikaido Ren is the captain of the Heavenly Wolves, a Chinese mercenary group and currently one of Katahara Metsudo's Bodyguards. He represented Byakuya News during the Kengan Annihilation Tournament, after stealing the affiliated fighter position under Toyo Electric Co.'s orders. Ren possesses an androgynous face with sharp eyes surrounded by black eyeliner, sharp eyelashes, a hairless visage and black hair set in a side-parting, with one side being swept over the left side of his face. He has an extremely toned but lean physique. He tends to have a stern, unnamed expression on his face and wears a sleeveless chángshān with floral patterns down the right side. Ren is a decidedly narcissistic person with a firm belief in his own strength, his narcissism is blinding, living to the beat of his own drum and being completely oblivious to others' notice of it. He is deceptively forceful and willing to use lethal force to maintain order.

Spoiler

During the main tournament, after Murder Music forfeited to Toyo Electric Power Co., Sawada Keizaburo called Julius Reinhold out for the dirty tactics employed by Hayami Katsumasa. Saying he would take the three of them down, Sawada attacked and Meguro took him on first. With Meguro getting too riled up, Ren prepared to calm him down while Julius stepped in to take care of Sawada. Suddenly Yamashita Kazuo and Tokita Ohma appeared with the former hitting Julius on the head with a can. Perceiving Yamashita to be a threat, Ren attempted to take him out, only to be left in shock when Yamashita seemingly dodged the attack. The three of them then left.

Spoiler

Later, representing Byakuya News in the main Kengan Annihilation Tournament, Ren fought Kiryu Setsuna in the first round. Quickly overwhelmed by his opponent, even after using the Heavenly Wolf Fist's secret technique, Ren was defeated and left in a bad state after Kiryu showed his true colours and sadistically finished their fight. Being revived by Mei, Ren wondered in shock just what he had fought. After his exit from the tournament, he and the Heavenly Wolves went to work on planting bombs around the Kengan Dome.