Inspired by the beginning section of the anime's Sengoku Basara II's episode 7, where Sasuke is reporting to Shingen and wants to stay by Yukimura's side but is told by Shingen not to. :) I'd really suggest watching it. It's an intense scene that just really shows how attached Sasuke really is to Yukimura.
This has some graphic imagery and some angst, could be unrelated. Also, several explicit chapters were removed and can now also be found on my livejournal under Shadow
As Lord Shingen had once said, it was a trial for you to let go of something precious that you had raised, and to entrust in them to handle whatever came their way. It was hard for Sasuke- forced to watch his master suffer and being unable to stop or soothe his pain. He could bandage his injuries and give him some careful words of advice- but Lord Shingen's words echoed within his head. He couldn't baby Yukimura forever, easing his way all the time. He had to let go and let Yukimura grow… and to grow, he needed to get and be hurt- mentally, emotionally, physically.
Sasuke hated it. He hated every new scar even as he smoothed healing salves over them, but he hated Yukimura's darker eyes even more. Those indicated scars that he couldn't soothe- wasn't allowed to. He wanted so badly to be able to. Sanada-no-danna had always been his ever since the boy had been very young. Always. Always… and it hurt so bad to let go.
Sasuke finally cracked- because his young master was stupid and sacrificing- so very stupid.
"I accept his punishment instead." Yukimura declare without hesitation, and Sasuke's strength collapsed in on itself.
The shinobu's breath became labored and his eyes blurred, and the ninja's hands shook as they reached up and clapped over his ears. Sasuke turned his back, not caring to see all the looks of surprise and concern he got from the foot soldiers. The clawed tips of his gloved fingers dug into his hair and drew blood, but Sasuke screwed his eyes shut and desperately tried to focus instead on the roaring of his blood pushed by the pounding of his heart. The shinobu's legs trembled, so he sunk down to his knees and dug his fingers harder into his skin.
He wouldn't watch- he wouldn't. If he did, then he wouldn't be able to hold himself back and he would shame Yukimura. But it was too painful to bear watching, so Sasuke chose to suffer in ignorance. He wouldn't watch, wouldn't listen. Sasuke didn't care if his actions were viewed as cowardly-let them call him what they wished, maybe this did make him a coward. But he absolutely refused to watch Yukimura, his dear treasured master, willingly bear brands of servitude on his skin to free slaves.
The soldiers' loud murmuring could be heard. Sasuke pressed his hands tighter over his ears.
A horrid stench wafted through the air. Sasuke held his breath and trembled.
He wouldn't watch so he couldn't act. His master chose this punishment. He would accept his master's word and bring himself pain before he brought Yukimura shame.
It hurt. Yes, it hurt very badly. Because despite his efforts, Sasuke still saw Yukimura's tender skin split and burn and bleed under the hot iron brand- still saw his master's gentle face collapse in agony- still heard the raw sizzling of burnt flesh and the despairing sounds that slipped through clenched teeth- still smelled the burning skin. Through his mind's eye, Sasuke experience it all anyways, and no matter how hard he dug his clawed fingertips into his skin, his suffering would not lessen.
It was an eternity before a familiar hand fell weakly on his shoulder, but Sasuke refused to release his senses. The shame- he wouldn't be able to bear it. The hand slid up to loosely clasp around his wrist and fruitlessly tugged, no doubt alarmed by the blood that was surely there from his self-inflicted wounds of restraint. Forgive me, Danna, Sasuke mentally begged without outward movement. I cannot bear it.