The burning and crackling sounds that can be heard from the other side of the door that I've closed gradually disappeared.

Perhaps, the oxygen inside the room has run out and it has been extinguished.

However, the slime is still alive inside.

The【Sword of trial】's『trial』count is still 0.

Since it's apparent that a back draft will occur if the door is opened, I have no choice but to give up this room.

「But, it's troublesome.」

When the【sword of trial】isn't properly used, the monsters will be blown away.

And, when the monsters hit the wall, they will catch fire.

When I appraised the dungeon's wall, it seems to be made of【red phosphorus】.

Speaking of【red phosphorus】, it's a component used on the striking surface of a matchbox.

In other words―

the red slime is the tip part of the matchstick.

The dungeon walls is the striking surface of the matchbox.

A large amount of oil on the floor.

It's not strange if it becomes sea of flames anytime......

I braced myself again and sneaked a look at the next room.

As expected, a red slime has been stuck on the ceiling.

When I approached carefully, the red slime attacked from the ceiling.

I drove the heavy【sword of trial】into the red slime with the intent to slice it off.

The red slime was cut into two with a single stroke,

and a red【slime's nucleus】came out from the inside of its body.

The appraisal result was【red slime's nucleus】.

Then, the【sword of trial】's『trial』count has increased to 1.

「Finally, the 1st monster, huh......」

To put things bluntly, when a『trial』is cleared, I should kill another monster of another location.

The mithril sword will only be able to knock the red slime to the side...... if that's the case, I feel like I will lose.

Taking it seriously, I went to do the『trial』properly.

***

「The 30th monster, huh.」

When I defeated 30 monsters,

25【red slime's nucleus】,

5【red slime's nucleus +1】,

and 5【magic stone of ignition】

were the loots I obtained.

The slime that dropped the【red slime's nucleus +1】and【magic stone of ignition】was a slime larger than the other slime.

When I unintentionally looked over, I noticed that there's another door in the depths of the room where the 30th monster was defeated.

Although in the rooms so far there was only one door leading to a passage way, only here is two.

I have great expectation for this.

The door was in a slightly higher place and wasn't submerged in the oil.

When I opened the door, the was also no oil inside.

「I did it, it seems I can walk normally from now on.」

I took off the long trunks and wore sneakers.

***

The first door is followed by a short passage way but there's a big door at the end.

「Is it a boss?」

When I opened the door, there is a room about the size of a small gym.

And, there are stairs in the depths ahead!

However, the stairs aren’t leading upward but downward.

「The underground also have a second floor, huh......」

As I muttered so―

three slimes fell from the ceiling.

With three colors of green, red and black,

the green and black's size is about 3 meters in diameter while the red is about 5 meters in diameter.

「So it's the boss after all!

Aya will get angry if I defeat it alone~.」

Well, I'll kill you anyway.

I mean, I will not go home until I kill 100 monsters!

To begin with, I used【appraisal】to the three monsters.

The green slime is a【Musasabi[1] Slime】,

uses wind magic,

after it jumps, it seems to glide like a flying squirrel.

The black slime is a【Darkness Slime】,

uses darkness magic,

it lurks in the shadows and seems to be launching surprise attacks.

As for the red slime in the center, it's a【Flame Slime】,

it seems to be spitting fire using the oil inside its body.

Let's defeat its follower while being cautious from its fire.

First, I started running towards the Musasabi Slime.

Then, the Musasabi Slime shone and a wind gust assaulted me. It would be the Musasabi Slime's【Wind magic】.

I dodged the wind gust with a jump and continued to launch a jump attack towards the Musasabi Slime.

The Musasabi Slime jumped backward and dodged my attack.

I jumped towards the same direction too and chased after it.

The Musasabi Slime opened its gliders to stop in the air and dodged me who was chasing by gliding. A Musasabi indeed.

My jump's momentum was too strong, taking me to the ceiling. I turned myself upside down and landed...on the ceiling.

And then, I jumped down from the ceiling and charged at the gliding Musasabi Slime―

*Slash!*

the Musasabi Slime was cut into two with a single stroke.

When the Musasabi Slime split into two, I continued to fall as is.

At that moment, when I sensed【danger】diagonally from below and looked―

the Flame Slime spat a flame towards me.

「Can the flame reach as far as this position?」

When I promptly hid behind the Musasabi Slime, the flame swallowed me together with the Musasabi Slime.

「Hot!」

Since I hid behind the Musasabi Slime, I somehow managed to survive without problems but my hair got burnt a little.

I landed safely and glared at the Flame Slime.

「Huh? Darkness Slime?」

At that moment, I sensed【danger】from behind―

as I was turning around, I counterattacked the Darkness Slime which made a surprise attack from behind.

However, the immediate attack didn't go smoothly and blown the Darkness Slime away without cutting it.

I ran after the Darkness Slime which got blown away to the depths of the room with a dash.

I finally caught up with the Darkness Slime and when I was going to deliver the finishing blow, I sensed【danger】from behind. I canceled the attack and jumped to the side.

A flame swoop down the place where I had been before from behind, setting the Darkness Slime ablaze.

Or rather, the Flame Slime's attack just now was nothing but a friendly fire!

I rolled over and finished off the Darkness Slime which was covered with fire. Finally, it became 1-on-1 with the Flame Slime.

I have various experience when it comes to 1-on-1.

I've defeated the Flame Slime easily,

and the underground's first floor's boss has been cleared!

The loots were

【Musasabi Slime's nucleus】,

【magic stone of gentle wind】,

【Darkness Slime's nucleus】,

【Darkness reinforcement magic stone +1】,

【Flame Slime's nucleus】,

and【Magic stone of oil】.

What's a【magic stone of oil】!?

┌─＜Appraisal＞────

│【Magic stone of oil】

│A magic stone which oozes out flammable oil.

│The amount increases when magic power is poured in.

│Rarity: ★★★★

└─────────

Isn't this amazing!?

[1] Japanese flying squirrel