Pain was nothing, had to be nothing. Soubi closed his eyes, willed himself to believe it, to keep himself from crying out as the whip fell, tearing open not-yet-healed wounds and creating new ones. He felt his teeth go through his lip, blood trickle down his face as it did down his back.
The pain grew, until it felt like a living thing, a butterfly like all those around him, trapped within his chest, beating its wings frantically as it slowly died. Died as Soubi's imperfections must die. Pain was temporary, delicate as his Sacrifice was delicate, but unlike Seimei, he must not obey it. Soubi had to be perfect. Nothing less was worthy of Seimei, of everything Ritsu-sensei was crafting him to be.
When Seimei took the knife, carved his name on Soubi's skin, he was grateful for those lessons. He didn't flinch, didn't pause in stroking Seimei's hair lovingly. Pain was nothing; he could move past it, be proud that his Sacrifice wanted to claim him like this, to decorate his skin himself. He didn't allow the discomfort of the moment to distract him, wanted nothing more than this.
But when Seimei died and he was left alone, knew that he had failed to protect him, Soubi learned that even the perfect Fighter, the one who never lost, could cry. Some pain wasn't temporary.