They were not heroes. None of the villagers understood this simple fact. In their minds, the Legendary Sannin were the greatest heroes of Konoha in generations. She was the Slug Princess, granddaughter of the First Hokage and the most gifted medical ninja in the known world. She had saved thousands of lives, shinobi and civilian alike, and singlehandedly crippled Suna in the war with her skill with antidotes. She was powerful enough to fight alongside Jiraiya and Orochimaru, strong enough to split apart the earth with a finger, clever enough to treat any wound or poison, and famous enough to be praised the whole way through.
They didn't understand what it meant to be her. How she could clearly and explicitly feel bones splintering to dust and organs tearing with every punch. How she slit her first throat, a young man sleeping beside his wife, when she was 6 years old. How over and over again she could feel herself die as her chakra vanished along with that of the person she had failed to save. How she slowly, one-by-one, lost the few people she loved. How she knew that each enemy she killed was someone else's precious person who would never come home. They didn't know and they didn't want to know what it cost to live their lives.
They didn't understand why she flinched every time a small child said she wanted to grow up to be like her someday. Why nights spent alone in shady bars were better than going back to an empty dusty apartment. Why that apartment was still better than any village festival or celebration. They didn't understand why she would leave.
They didn't know how much she hated their naive praise. How she cared nothing for them as individuals. How she was just doing her duty simply because it was the only thing she knew how to do. How she painted her nails red to cover the blood she could never fully remove from under her nails. How her dreams were haunted by children screaming and guts falling out and dead eyes that wouldn't stop staring at her. How she would burn the whole village to the ground in order to bring her loved ones back to life.
No they were not heroes. They killed unquestionably and then they went to bed covered in blood. They killed on orders or on a whim, but Tsunade couldn't seem to remember a single time they killed out of necessity. But they were not quite villains either. No one fighting to protect something precious could ever truly be a villain.
For all her lack of love, Tsunade couldn't bring herself to hate the people she was fighting, the same ones killing her comrades. She couldn't hate them because they were like her, just with a different view. For all the wrongs done to her, she knew that she had hurt them right back. She knew that while they came from different lands, they had the same nightmares as her and they knew the same pain and they did not hate her either.
No, there are no heroes or villains. There are just people and what they do to each other and how they deal with it.
She would have to find a way to live with it, with all the things she did and didn't do, with all the words she had forgotten how to say, with all the memories she couldn't quite let go. And until then she would order another drink and play another hand.