I doubt he killed the kages, my guess is as soon as he felt the nine tails chakra he shot off to the scene when naruto used them tails in this chapter.
and naruto will die if the chapters progress, the only thing I can think of is sasuke or obito teaming up on madara. and obito using izanami or izanagi to sacrifice himself to kill madara, and then fails.
and then madara rules the earth while everyone trains for hundred arcs to kill him. blabla