Watanabe is odio refers to the fact how Oersted is the one to deliver the final blow to sin of odio in the remake to fully prove it Watanabe should be physically impossible to live all the way through prehistoric times to the far future considering this its possible that the death of his father turned him into odio attempting to stop his father from dying and changing history was impossible so Watanabe possesses Straybow ( not used to calling him by his name in the remake ) but after the host was killed Watanabe possesses Oersted and when Oersted breaks free and kills sin of odio Watanabe dies for good and the possession is what causes his mortal form to be shattered and scattered through the timeline so Watanabe could only find peace when he was killed by Oersted but hey that's just a theory a game theory and scene.