Madara is not bluffing. He is not serious.
If he was trying to kill them, he would not be talking no jutsu so much, first of all. He is basically telling them everything that he's about to do as he is doing it. He is not scared of them knowing his strategy and he seems to have a completely new move that no one has ever encountered every week.
If he wanted them dead he could have sent his clones after them when they originally passed out from the pollen. Or just drop another f**king comet on they @$$. If he was serious he would also be using help from the other revived Edo TsuckiKage on the scene, but he hasnt even spoken to him since he was revived. lol. Plus he keep whining like a b***h because he cant fight Hashi no more and his descendents are a JOKE. They may prove themselves worthy otherwise later but for now lets just say Madara is so much in control at this moment he could literally leave the battlefield to fight his family and the Kage might STILL die to CLONE versions of him. Damn.