Murakumo :

he is a mysteriously appears wiht unknow motives, but he soons proves to be on the aragami and connections to Keade. He is stronger that Kusanagi because he has 8 mitamas, but his will ins't as strong.

Valencia Tachibana :

Valencia is 16 years old. He appears in the first part of Blue Seed 2. She likes Kusanagi and has mitama which give her great powers. She also has information on the new aragami's that hve showed up. She joins the TAC to help them. Her motive and background is still uncertain