I thought about sth. A lot of people give kabuto the first place because of edo tensei. but how kabuto could beat edo madara who is a free person now? unlimited chakra and undying body, mokuton on hahiramas level, rinnegan and perfect susanoo? one slash of perfect susanoo crushes all edo tenseis. and madara can send out clones to fight them with susanoo while the original will control kabuto and bring him to end edo tensei.