OK. How can you justify Madara toying with Hashirama? Do you think that Madara, leader of the Uchiha, would toy to the point of dying at the hands of Hashirama, his rival personally and in terms of the clans, passing superiority to the senju? Even if the toying or not using full power is justified by him wanting to get his DNA? DNA lasts even after you die, so unless your telling me that he didn't have a jutsu that could kill him or even stun him (if for the purpose of DNA) without completely incinerating him without a single trace left behind, than this cannot be used to justify. Although, considering Hashiramas power and healing ability, this could be true, this is entirely possible, I don't believe it and it cannot be proven. Even if he was toying, and did turn out to be the stronger brother, why wouldn't he go all out when he was realizing that he was gonna die? Makes no sense no matter how you look at it. BTW you don't toy by bringing out the most powerful known beast as a partner in your fight. What I will say is that with Hashiramas cells and the rinnegan Madara is probably stronger than Hashirama, and that, due to context clues given by minato, he might have lost control of kurama, resulting in his defeat.
Whatever the case, Madara just lost. Get over it.
Whatever the case, Madara just lost. Get over it.