Tobirama the younger brother of the head of senju clan was given to madara the head of Uchiha clan for peace between two clans. Tobirama had killed Madara's younger brother izuna in the war so he knew when he steps into Madara's house he wouldn't have peace for one minute. and well he thought right.

since tobirama entered Madara's house he faced different kind of pain and abuse, mentally, physically even sexually.

at first he tried to fight back, to resist but Madara was stronger than him defeating him easily breaking tobirama's ego, identity, soul, pride and everything.

well that's how Madara wanted to take revenge of Tobirama for killing his brother but he didn't really feel satisfied even after all those torture on Tobirama.

....

Madara entered the room his expression cold and stoic as always, showing a hint of hatred but also something else he couldn't put a finger on toward Tobirama who was sitting in the corner of the room.