Board Thread:Theories and Speculation/@comment-30355627-20170312130432/@comment-25632268-20170312193747

Kakashisologod wrote: @Thekillman he had the option to:Absorb all of their jutsus,absorb their chakra and somehow BZ can walk up to him and he dosent sense he is trying to kill him.

He didn't sensed that Obito will stab him and steal part of Shukaku and Gyuki chakra as well. I think Madara was just too full of himself to even try and sense anything as he was 100% sure Obito is fully controlled by Black Zetsu.