The stairs to the next level appeared in the back of the room after the boss monster was defeated.

Storing the dragon's corpse in his subspace, Ryu proceeded.

There was a magic circle for dungeon escape in the room at the bottom of the stairs, and no monsters could enter this room.

Beyond that, there were several more levels, with ferocious monsters such as trolls, ogres, and minotaurs. The boss monsters were all high-ranking dangerous monsters, including higher-level variants.

Of course, no matter how high-ranking and dangerous the monsters were, they were simply stripped of their magic stones and instantly killed in front of Ryu.

(With Ryu's power, he could easily win in hand-to-hand combat, but extracting the magic stones was too easy for him to stop.)

And finally, the lowest level, the dungeon's overall boss monster was the Hydra.

The Hydra is a multi-headed dragon monster, also known as a poison dragon. Its venom is so deadly that it is said to be able to kill even gods. It also possesses incredible regenerative abilities, and even if one of its heads is cut off, it will quickly regenerate.

And this Hydra, despite being a dragon, had a low intelligence or was just too brutal, perhaps both. It didn't obey Ryuzeen and a fight ensued.

As Ryuzeen was immune to all poisons, the Hydra's deadly venom wasn't much of a problem.

As with previous boss battles, Ryu tried to extract the magic stone first, but the Hydra regenerated its magic stone immediately. (In a way, it could be called a delicious opponent because you could collect the magic stone repeatedly.)

It is said that the Hydra will die if all its heads are cut off simultaneously, but in reality, that is not enough. All the heads will eventually regenerate.

Moreover, it doesn't just regenerate; the severed heads split in two and regenerate, increasing the number of heads. The regeneration speed is abnormally fast. While cutting off one head and then another, the previously severed head regenerates. Moreover, the number of heads increases with each regeneration. The more heads there are, the more toxic breath spews out of their mouths. Furthermore, despite its gigantic size, it moves incredibly fast, too fast for an ordinary person to keep up with.

But Ryu has the "Magic Sword Fragarach," which has the ability to inhibit regeneration. Ryu, wielding Fragarach, cuts off one of the Hydra's heads in a single blow. Ordinary steel swords cannot even scratch the Hydra's hard scales, but the sharpness of Fragarach is among the strongest in the world.

However, while the cut area does not regenerate, the remaining heads bite off the severed head from even closer to the root, and two more heads regenerate from there.

I see. So that's the countermeasure for the non-healing wound caused by Fragarach, thought Ryu, impressed. Quite a troublesome opponent.

In the end, Ryu had to use his time acceleration ability to the fullest. Ryu deviated from the flow of time, slowing down the flow of time around him. When that ability reaches its peak, time stops.

In the stopped time, he cut off all the heads. He severed all the heads simultaneously with a regeneration-inhibiting sword, so they shouldn't be able to bite off and revive. But the poison dragon used its claws to cut off its own head. Does it not understand, or is it actually intelligent?

Ryu hurriedly stopped time again and cut off the regenerated heads and the arms with claws attached. Just in case, he cut off its hind legs too.

However, when time resumed, only the torso remained, but of course, it was still alive. And it breathed fire. How it breathes is unclear; its physical structure is unknown, but flames burst out from the severed head's cross-section, burning the cut surface, which caused the head to regenerate.

Ryu cut off the regenerated head, extracted the magic stone, and chopped up the torso, finally succeeding in killing the poison dragon.

Quite a troublesome opponent. I doubt even an A-rank adventurer could take it on. Maybe an S-rank adventurer, of whom there are only a dozen in this world, could do it… but I've never met an S-rank adventurer, so I can't say for sure. But I think even an S-rank would face a tough battle.

At this point, conquering this dungeon would be virtually impossible.

…

…

…

After defeating the dungeon's boss, Ryu checked his surroundings with spatial awareness and found a small room behind the back wall, even further back.

There was no entrance, so he ripped the wall apart with the magic sword Fragarach, causing it to crack and crumble.

Inside, there was a pedestal with a melon-sized sphere half-buried on it. The dungeon's core.

Destroying or taking this core would kill the dungeon, turning it into a simple cave.

Ryu picked up the dungeon core and stored it in his subspace.

As a resource, the dungeon would be gone, but there was a demolition order from the lord anyway, so it was no problem.

Ryu has a lot of materials in his subspace storage. He can just release them little by little, and he won't have any trouble with material distribution for a while.

In this city's scale, buying a few dragons' materials would blow the budget. However, Ryu's subspace storage still holds materials from over a hundred dragons, as well as the Hydra, which was the dungeon boss.

He won't be able to hunt in the dungeon anymore, but he can just sell them little by little, and he won't have any trouble with material distribution for a while.

In fact, Ryu has already made enough money from recent hunts and sales of their materials to live the rest of his life without working.

…

…

…

…

…

Ryu returned to the Adventurer's Guild and reported that he had conquered the dungeon and that Big and the other "Red Meteors" had died in the dungeon.

The staff member who heard the report hurriedly went to call for the Guildmaster, Daniel, and a commotion ensued.

Daniel: "Ryu, you didn't… you didn't kill Big and the others, did you?!"

Ryu: "That's harsh. When I said I was abandoned, you wouldn't accept it because there was no evidence. Now you're saying I did it without any evidence either?"

Daniel: "……You have no proof that you didn't do it."

Ryu: "Give me proof that I didn't do it? How? Well, let the Guildmaster himself give proof that he didn't kill Big and the others."

Daniel: "… Damn it, stop being so pedantic."

Daniel gave up and retreated to his office.