Kishi really favors the Uchiha. It's one power up then another. xD About Izanami, It's been said that Izanagi is the opposite of Izanami if I guess right? so I think since Izanagi turns reality into illusion, Izanami will turn illusion into reality. Like when Itachi casts Amaterasu in his genjutsu, he could bring it down in the real world instead. Or since it's a genjutsu, he can use Chibaku Tensei, Rasenshuriken or even turn Kabuto into puny little snake then Itachi kills it. LOL just a guess though