To be honest, this whole drama is unnecessary, he has a seal that prevents anyone from feeling him, and chakra chains that prevent the use of chakra...all he has to do is wait in a precise location and he could easily kill Danzo.
Kaito gotta get his getback on Danzo already, he's being held back by his sensei and the Hokage, if this keeps up he might have to become a rogue-nin in order to kill Danzo