I could write a whole essay about that encounter, holy moly! 😮💨✨
When the Allied Shinobi Forces were left in a desperate situation against Madara in the Fourth Shinobi World War, it was the resurrected Itachi Uchiha, who persuaded Tsukino to intervene and join the fight against her husband.
With suppressed chakra, Tsukino faced Madara, knowing full well that it would be her last fight. Through her Byakugou Seal she´d stored chakra over decades to keep herself young and prevent herself from dying. As a veteran of the First Ninja World War, sister of Hashirama Senju and user of Mokuton-Jutsus, she was one of the most powerful Shinobi, yet fighting against Madara would require immense usage of Chakra and could lead to an instant death if her seal would break. It was an immense risk she took, but she did because she was horrified by the things Madara had done up to this point. She needed to be his end - and die in the process.
At first she didn´t show herself - as said - she appeared on the battlefield in disguise with a tengu mask that covered her face. It wasn´t just to hide herself but also because she couldn´t bare to look Madara in the eyes. Even though she fought like a thunderstorm that crashed over Madara, it didn´t took long until he recognized her Jutsus from the time they'd fought on opposite sides in the First Ninja World War. When her mask broke, it revealed Tsukino´s scarred face - she was alive, which Madara didn´t know before. His plan was to bring her back sooner or later through the reincarnation Jutsu and free her just like he did with himself. But since neither Kabuto nor Obito had found her body, seeing her alive was the explanation for it.
But their encounter was not as happy as both of them had wished to be. Madara noticed right away that he was there to fight him, which for him was amusing. He tried to persuade her to join his cause, calling back the deep love he still felt for her - that they were still husband and wife. Yet Tsukino resisted, even though it was a painful thing to do. On her side she tried to convince Madara that he could stop this War once and for all, but he was too far gone with his plan to back off at that point. So there was no way out of a fight of life and death.
