Attila the Hun
Found by Jack in ancient China (despite the real Attila the Hun living in Austria-Hungary), he battles Kimiko.
Found by Jack, he battles Raimundo.
Billy the Kid
This gun-slinging cowpoke is a perfect opponent for down-home boy Clay.
Arguably the most evil person on the team, she battles Omi with a yard stick and often tells Jack to go sit in the corner.
Old Jack is Jack from the future. With his knowledge of the Shen Gong Wu, the team was able to find the Shen Gong Wu before they revealed themselves.
Technically not part of the team, but was with Jack at the time.