Doomguy X Demon Slayer

The Portal

Doomguy awoke and bust out of his coffin. The Maykrs showed no signs of shock or surprise, and instead Samur Maykr exclaimed "Your time has come again, Slayer. You will fight the same foes, but this time, they will be a little different. You will have to go back in time and visit the nation of Japan. They are not the roots of all existing demons, but they impact the timeline greatly. You must fix this, Slayer."

Doomguy had no problem with this task and simply nodded to this command. He was brought to a portal that would bring him to the world where his soon-to-be-enemies would prove themselves to stand out as demons by gallantly showcasing their strange abilities to him. In contrast to this snarky showcase, he wouldn't care and probably wouldn't try to care at all.

As he stepped into the portal, a light blinded his vision. He woke up in a bed, still clad in his almighty armor. The homeowners saw his incredible height and strength as he stood up. He looked like some kind of "demon slayer" to them, but soon, he would be far greater than that.

As he walked out of the house, he traveled into unknown places and quiet areas. In all of the days he traveled, not once did he ever get tired. Until that strange day. Doomguy saw a young woman eating something like how a wolf would eat a deer. He looked closer to observe as he hid behind thin trees, and it was not just something... it was someone. Doomguy what his task was and had to kill this newfound demon, but he saw a boy with long hair approaching the estate giddily. He resisted the urge to stop the boy in his tracks as he hid behind the trees, and merely observed as he limited himself from intervening. But why? Why would Doomguy not help this boy? The boy finally got home and his giddy behavior went silent. He stood in shock and stepped back as he found his family dead...

The boy revealed himself to be none other than Tanjiro Kamado. He stood there staring at his sister while she ate the family alive.. Doomguy could do simply nothing but watch all this violence. As the sister began to tackle Tanjiro, Doomguy knew had to do something. But just as he prepared to strike, a demon slayer appeared in the midst and tried to kill the sister of Tanjiro... but something happened that would make Doomguy facepalm. Tanjiro defended his sister and claimed he could "tame her" in such a way that she could become civilized again while still a demon. Doomguy was so disappointed and angry while watching the mere people argue at each other. The demon slayer Giyuu Tomioka decided to leave this pathetic boy alone with his unreliable demon-sister. Doomguy decided to follow Tanjiro in a secretive style so that he wouldn't notice.