I haven’t posted a KiyoKuro AU in a while so here goes:
AU where Kiyoshi is a healer, sin-eater, and crown-jewel of a major temple, and Kuroko is given to him as an “outlet” (read: consort) because his “job” is both mentally and physically taxing.
As a healer and sin-eater (somebody who “absorbs” the sins of others to absolve them of guilt, while at the same time burdening themselves with said sin), Kiyoshi is seen as a god of sorts, but he holds no real power as the only ones allowed to receive his help are those who are wealthy enough to pay the owners of the temple. Kiyoshi feels duty towards the people, but is otherwise naive and has no real idea of what the outside world due to his isolation.
Kiyoshi heals by serving as a conduit between the people and the gods--he absorbs their suffering and ailments so that the gods may lift it off his shoulders. Needless to say, it takes a great toll on him, and he is eventually introduced to Kuroko, whom he’s encouraged to use as he pleases.
Kiyoshi’s happy to have the company, but finds it to be in bad taste to use someone as passive as Kuroko as any kind of outlet, whether it be emotional, physical, or even sexual. Kuroko insists that he’s willing, Kiyoshi is dubious, but Kiyoshi doesn’t remember that Kuroko was someone he had healed in the past despite the latter being poorer than his usual clients. As a result, Kuroko feels eternally indebted to Kiyoshi (and not the temple, which is important).
They grow close, Kiyoshi’s happier than he’s ever been as he learns about the outside world from Kuroko, and the temple is at its peak.
One day, a very angry and very influential client accuses Kiyoshi of deceiving him and indirectly causing the death of a family member. He demands retribution from the temple, but harming their crown-jewel is out of the question, so they decide to take his only possession--Kuroko-- and bring him to the altar.
Kiyoshi pleads to them first to spare Kuroko, when they don’t listen, he turns to the gods whom he had pledged everything to and served tirelessly. They don’t answer, and when Kuroko’s blood flows from the altar, Kiyoshi comes to a horrifying realization:
The gods don’t accept the suffering of mortals because they are benevolent. They take the suffering of mortals because they like the taste of it, and Kiyoshi’s, their dearest priest, is the most delicious of all.
And it’s as if everything he’s lived for--his admiration for those he served, his ability to help others, and Kuroko--disappears all in a matter of minutes, and for the first time in his life, Kiyoshi curses the gods, the people, and the temple-- so much that he catches the attention of another god who had always been excluded from the pantheon-- the god of death.
When he’s alone for the first time in years that night, the god of death appears to Kiyoshi and proposes a deal--serve its agenda, and it’ll give Kiyoshi an opportunity to wreak vengeance on the gods that abandoned him.
Its agenda? To kill every single god in revenge for sullying its name.
Only gods have the power to kill other gods, and on top of that, they feared Death and excluded him from their ranks while teaching humans to fear and despise death. Divine laws were created to keep Death in its place, but Death finally finds its loophole through Kiyoshi--a human regarded as divine by his own kind, and now very willing to bring his vengeance to the heavens.
Kiyoshi accepts Death’s scythe and lays waste to the temple and its masters, finally recognizing it for what it was--a shrine of corruption that embraced the wealthy and shunned the poor and most vulnerable of society. In that aspect, he finds that mortals and gods could be very similar.
Death takes on human form, resembling Kuroko. He accompanies Kiyoshi as his guide and support, while the other treks the land to hunt down each god one by one. The irony of it all doesn’t bypass Kiyoshi, who had always looked forward to finally exploring the outside world with Kuroko at his side.
On his journey for vengeance, Kiyoshi doesn’t completely lose his sense of obligation to help others. In the villages he stops at, he does his best to heal whomever he can while vehemently denying monetary payment (even the sight of gold coins is enough to set him off), but the deeds prove taxing, especially when he no longer offloads the burden to the gods.
Death chastises him at first, but eventually offers to take the suffering off of his shoulders even though it doesn’t really have a taste for human suffering. Kiyoshi rejects it at first because even though Death is on his side, the last thing he wants to do is establish that link with another god. Death calls him stupid and ends up siphoning the burden from him while he sleeps anyways.
It comes to be that Kiyoshi actually succeeds in killing every major god within the pantheon, and he realizes that Death wasn’t in it for revenge, but rather to free humanity from their corruption and false promises. When Kiyoshi turns the scythe on the minor gods, Death stops him and tells him to rest.
“But I’m not finished,” he protests, while realizing at the same time that he is on his last legs and the only reason why he wasn’t dead yet was because he was working WITH Death.
And even Death was tired of watching him suffer, from the time he was a child, to now, he never lived a day where he wasn’t serving a god in one form or another.
Death asks him to rest again, tells him that the ones most responsible for his suffering are gone now, and in due time, the minor gods will fade away as well. As Kiyoshi threatens to collapse from being devoid of purpose, Death offers compensation for the toll it took on Kiyoshi’s mortal life. “You performed beyond my expectations. Humans would call this a “bonus”, correct?”
Death undoes its taking of Kuroko’s life and reunites them. Kiyoshi’s overwhelmed with happiness, confusion, and disbelief, while Kuroko doesn’t seem very confused at all.
Death had heard both of Kiyoshi’s prayers from that fateful day--the one for vengeance, and the one for Kuroko’s life. Kiyoshi wonders why it hadn’t brought Kuroko back sooner if that was its intention from the beginning, and Death explains that while Kiyoshi was on his journey for vengeance, Kuroko was on his own to find him before entering the living world again, and Death had guided them both (while talking with Kuroko to learn more about Kiyoshi, which Kiyoshi finds embarrassing “you two were talking about me??” Yes, they both answer in that same tone of voice. “Kuroko gave me permission to use his face too,” Death adds.)
With the added blessing that they will eventually leave this world at the same time, THEY LIVED HAPPILY EVER AFTER!!!!!