Well itachi said madara went blind and took izunas eyes, but after learning izuna was slashed by tobirama and died of infection im starting to think that madara took izunas eyes because izuna was dying and not because he was blind, so on izunas deathbed madara made a promise to bring him back and izuna took madaras eyes and died, then madara fought hashi apparently with the intention of losing and stealing his dna or wutever so he could achieve rinnegan and give the rinnegan to nagato who would revive madara or maybe the plan was both madara and izuna or even the whole fam lol. Nagato and obito betrayed him so he was planning on becoming juubi jin and probly coulda revived izuna without losing his life but that didnt work so he will use edo tensei so izuna can help him, and why stop at izuna he did say he had 5 brothers and dont forget daddy
i think, from seeing madaras flashback, its already apparent that madaras brothers are his driving force not tsuki no me that was for obito.