Well I have been thinking that Kurama(nine-tails) knew exactly the power of Madara as he was controlled by him during his fight Senju Hashirama. And when Kurama was almost extracted from Kushina by Tobi(Uchiha Obito), he recognised the chakra. And during the Fourth Ninja War, when EDO MADARA appeared and tried to summon Kurama(who was still inside Naruto), there also Kurama recognised Madara's chakra and told Naruto that he would choose Naruto over Madara. SO my question is - Is the chakra of tobi/obito(who attacked Minato) tha same as that of Madara(who fought with hashirama)/Edo madara? Please share your views.