Kimetsu no yaiba: Ancient Evil

Under the city.

ONE WEEK AGO.

Date: April 8th

Mission report: Creeping ashes.

Kazan: A crime family huh. Despite being such a dangerous city there isn't much activity up here.

Kazan looks around the city, jumping from rooftop to rooftop.

Kazan: Without a doubt, there's demons all over this city, they're all underground. Now... How do I get under the city?

He lands on top of a large fountain located near the center of the city, he looks into the fountain seeing deep within the water there's a large opening.

Kazan: I'll just have to brute force this I guess.

Kazan jumps far back, breathing in and preparing to punch the ground in. Kazan jumps straight for the fountain.

SCREEEEECH.

Kazan stops in his tracks as the fountain opens in the center. A small group of people stand in the now opened center, lowering them down into the city like an elevator.

Kazan: Well there we go.

Kazan jumps down the hole as the fountain closes. He pulls two kunais out as he stabs them into the walls around him, slowing his descent. He stops right before the walls end, revealing a massive underground city to him.

Kazan: To think the city of Anastreptos had all of this underneath it, impressive. A demon for sure built everything down here.

Kazan slowly descends down using strings wrapped around him and his kunais.

Kazan: No matter how beautiful this place may look, it's crawling with demons. That crime family is most definitely down here.

Kazan drops down on a building as he overhears a conversation between someone in an alleyway.

Demon: Apparently one of our warehouses was attacked today by some demon slayer. Master wants all four of the branches to meet up, not just the executives. He's calling for every leaf in the city to be there.

Kazan turns to his side and notices a tree carved into the building.

Kazan: Crime family "The tree". The weak ones are leaves, executives are branches... All being led by the upper moon. Seems Kaiyo already got noticed... Bound to happen either way since we needed to attack them somehow.

Suddenly both demons are thrown onto the roof that Kazan stands on. Kazan quickly ties them up.

Kazan: Alright you guys, I need to know everything you know. All entrances and exits to this place, executive names and abilities, and anything about your leader.

Demon: I ain't telling you sh-

Kazan swiftly cuts his head off.

Kazan: You tell me. I won't make your death nearly as fast as his.

Demon: O- O- O- Okay! I'll tell you what I know!

Kazan: Good...

The next day

Kazan: I'll take advantage of them being in a meeting and I'll go ahead and map this place out. Knowing every entrance is great too.

Kazan jumps around the city drawing out each and every building, wall, and entrance onto a large piece of paper.

Kazan: I need to know everything about this city, every little detail.

Kazan spends the next few days drawing out the entire underground city.