"Humans are soft, brittle, weak. They die right away."

An Upper Moon Demon stood tall in front of him. He, Akaza, is grinning too wide for Giyuu's liking. He is showing the expression of superiority as he just beaten up two demon slayers at once, with one of them is the water pillar himself.

"And they easily disappeared into nothingness."

Akaza takes few step closer to him.

"Except you. You're different. For all weaknessess that human had, I am amazed at how you lasted this long. Such an indomitable spirit you've got there. And I will offer you something that indeed suitable for you. Something that will overcome your weaknessess as human being."

Suddenly his expression become devoid of any emotion.

"Are you interested to become a demon, Giyuu?"

"What-"

"No, that's not come out right. Become a demon, and don't let the dead caught you like what happened to Kyoujuro and soon, Tanjirou."

Giyuu look at Akaza's eyes with suppressed anger.

"Tanjirou will not die."

"He will. No human will survive with having injuries like that. He is weak, and like another weakling, he will die."

"YOU-"

"I am waiting, Giyuu."

Giyuu tensed at that. Akaza's voice become cold, with tone of impatient and no room for argument. Giyuu stands up, and take steps closer to Tanjirou's body.

He scrutinized Tanjirou's unconcious form. Blood was covering his face, so much that he almost unrecognized if not for his signature haori. One arm bend in strange shape, but another one, thankfully, still in better shape. The water pillar crouched down, and carefully took tanjirou's hand, it feels warm and a bit clammy and giyuu refused to think that a hand he was holding will lose its warmness soon.

He never feel this terrified, not since he hopelessly watched Sabito left him to fighting the demon in their final selection. He needs to do something or another life will lose. Giyuu doesn't want that to happen. He is a demon slayer, capable of killing many demons. He had his sword, he was a pillar. And yet...

No, He won't give up here. He won't let his family and friend died in front of him again. He will save Tanjirou. Just like what Tanjirou would have done to Giyuu.

If only he can find a way to do that, anything, anything-

Giyuu's eyes widening. The realization struck like a lightning, as he finally found a way to save him.

But-

He tightened his hold at Tanjiro's hand. He shouldn't hesitate, as Giyuu will do anything for Tanjirou. Because Tanjirou is the most important person to him, the only person that he put his loyalty more than his fellow demon slayers.

To him Tanjiro's life is more important than his.

But his life won't be the same. He will commit something that can be consider as the biggest sin in Demon Slayer Corps. He will become a traitor.

"Well?" Akaza is getting impatient. Giyuu releases his hold, he takes a deep breath, and looks straight to man in front of him.

"I will. I will accept your offer. I will cast my humanity away and become a demon." It disgust him when he is seeing the demon grinning. "But with one condition."

Giyuu didn't expect him to agreed at his request. The water pillar already dreading the possibility of Akaza rejected his request. After all what he asked from him is something so bizzare and consider uncalled for.

Giyuu needs demon blood to save Tanjirou.

There is rumor among the pillar about Shinazugawa Sanemi's brother, that he keeps consuming demon blood. And this rumor even confirmed by Tanjirou himself. Demon had impressive regenerative ability and consumed their blood will help human to recover any fatal wounds. The more powerful the demon is, the faster recovery the human get.

"Allright, We gotta quick. I am gonna give my blood to him. After that, let's go to That Man's location."

Giyuu watched as Akaza bite the tip of his finger. The demon grabbed Tanjirou's jaw and and then shove his finger into his mouth. It doesn't take long to feed Tanjirou his demon blood.

"Let's go."

Akaza is heading first. Giyuu cast final glance at his comrade -his former comrade- before he is going too.

Tanjirou will mad, He will never forgive him. Giyuu doesn't expect him to, after all he commits the biggest sin for demon slayer can do. He never deserve forgiveness.

"Farewell, Tanjirou"

And when the time comes for them to meet again, they will fight each other to death.