Board Thread:Questions and answers/@comment-27279375-20161004220118/@comment-8695373-20161005042909

Without spoilers: Terumi removed himself from the Unit because it bound him to Amaterasu. In CF he needs a vessel ASAP and he no longer trusts Hazama, so Terumi wants Hakumen's body back. In his Act 3 he got the sword Hihiirokane, which can kill ghosts and such, and he wants to kill Hakumen with it, to get "the best vessel" for himself.

With spoilers: go read the Susano'o character discussion thread.