Disclaimer: I do not own Bungou Stray Dogs or Gintama.
AN: This is being written self-indulgently because for some reason I'm interested in the idea of Kamui in the mafia. This chapter will be short since it's a glimpse of my idea, I'll only write more if I feel inspired to. Naturally, this is a bit au to have the universes fit together.
Good will always triumph over evil. It is a very simple concept, but one taught and believed without question. A 'bad' guy is always wrong, and no matter how powerful he is, a 'good' guy will come along to save the day without fail. The 'good' guy always wins and becomes stronger.
Kamui never much liked these stories. He didn't believe in good or bad, only in strength. The person who came out on top was the strongest, not the purest of heart. The fact that he and the surviving remnants of his bloody race surely proved that. In the back of his mind he remembered a girl of that bloody race, but she was weak despite her pure heart. He pushed her from his mind. He didn't care about the weak.
On paper, Earth wasn't much and Kamui couldn't remember why he headed to the small planet in the first place. He liked to joke it was destiny, destiny he came to this planet and learned about humans with abilities. Chance that he asked to join Yokohama's Port Mafia and was allowed to join. It wasn't that rare, there was a small fraction of Amanto who took refuge on Earth and criminal organizations with brains recruited them to use their strength.
When asked by their leader, an oily looking man who introduced himself as Mori Ougai, he was very direct.
"The Mafia are bad guys, right? Good guys always rise to fight the bad guys. If I join the bad guys, I'll get the chance to kill all sorts of good guys. You'll let me, won't you?"
Kamui had asked with child-like enthusiasm. It contrasted with the blood dripping off his hands and the all too clear murderous intent wafting off him.
"And when you run out of good guys?" Mori had asked, eyes sharp and gleaming with interest.
"I'll look for more strong people to kill. I hear this country is crawling with them."
He didn't deny the possibility of turning on them in the end. He didn't bother with any false vows of loyalty. It was like he was asking to be included while not genuinely intending to be one of them. Knowing fully well Kamui could attempt to take even his own head, Mori accepted. It was sure to become an interesting development one day.