En (M1) - Student of Master Mitamura, 1st former member of Dr. Ichigaki Team, now was an ally of Yusuke during the Finals of Dark Tournament as part of Audience.
Ryo (M2) - Student of Mitamura, 2nd Former member of Team Ichigaki, now Urameshi's ally during the Dark Tournament's finals as part of the Audience, cheering for Yusuke and Team Urameshi.
Kai (M3) - Student of Mitamura, 3rd and last former member of Team Ichigaki and currently a Friend of Yusuke Urameshi and now Yusuke's ally during the Tournament's finals as part of the audience, supporting and cheering for Urameshi and his Team.
Enki - King of Demon World, former Friend of Raizen's and now Yusuke's ally.
Kokou - Husband of Enki, former ally of Raizen and now an ally of Urameshi.
Natsume - Twin Sister of Kujou, former Ally of Raizen and now Urameshi's ally.
Kujou - Former ally of Raizen's and now an ally of Urameshi.
Shu - Raizen's former ally, now an ally of Yusuke Urameshi.
Den-Hou - Raizen's former ally, now Yusuke's ally.
Tetsuzan - Former ally of Raizen, now Urameshi's ally.
Saizou - Former ally of Raizen's Alliance, now an ally of Yusuke's alliances.
Souketsu - Former friend of Raizen's alliance, now sided with Yusuke and part of Urameshi's alliances.
Hokushin - Former ally and Participant of Raizen's, now Urameshi's partner and Ally.
Touou - Raizen's former ally, now Yusuke Urameshi's ally.
Seitei - Former ally of Raizen, was now an ally of Urameshi.
Sayaka - a Spirit World Inspector sent to determine that Yusuke was a suitable candidate to return to life, was Yusuke's ally, but wasn't with Urameshi and his Team through the Entire Series of YYH.
Saitou, Sourai, Ohou, Ryuhi, Rinbai and Shun-jun - They were seen in the Chapter Black Saga as minor characters. In the Saga of the Three Kings, Saitō, Sōrai, Ōhō, Ryūhi, Rinbai and Shūn-jūn had become Urameshi’s allies in Episode 98 of Season 4.