merendinoemiliano: thank you for your advices and kind review! Do not worry, I don't plan to make this fanfic turn into smut anytime soon. And I don't plan to make my character a mary-sue either. He will be less OP or maybe equal in strength as then the main character of the manga :)

I can increase my own level!

Hiding inside my hole in the wall, I watched this new monster with wary eyes. It was a reptile who looked like a lizard. His most dominant feature was his giant yellow eyes. The fact he was eating the petrified part of the centipede was already a bit dreadful. He was chewing it like it was nothing!

The name alone revealed how dangerous the creature was:

" Basilisk "

If the name alone wasn't enough for me as a warning, this beast's eyes glowed and two spotlight turned the rest of the centipede into stone! I gaped... and unfortunately, this reptile heard me! I wasn't fast enough and as I retracted my head inside my hiding spot, my right ear was touched by that light and changed into stone!

A sense of dread gave me pressure as I was wondering my next move. I used my echolocation to check the basilisk location. I was dispirited as I saw it was climbing the wall to get me. I still had some of the centipede's remain and the only plan I could think of is to throw them once his head reach my hiding spot. By using my echolocation constantly, I was able to find out where he was even if I couldn't see him.

Focus, focus...

I putted my feet on the wall behind me and used my wing to lift the centipede remains. As he was about to show his head, I sprang in action and threw the centipede's remain. In the same time, the basilisk used his petrification gaze inside the hole. The mysterious voice popped up again:

" Skill Proficiency reached. Skill " Concentration LV.1 " has become learned. "

" Skill Proficiency reached. Skill " Petrification Resistance LV.1 " has become learned. "

Fortunately, the centipede's corpse absorbed most of the petrification and it surprised the basilisk. It made his head go back, revealing his neck. I used the wall behind me to jump to close in. I bitted him hard on its exposed neck. My mouth was so big that I was restraining his shoulders, making it unable to use its front legs. However, we no longer have a solid grip on the walls, which mean we both felt down to the floor below. I used his body as a cushion, making the beast pinned down and winded. I fortunately still had my grip on its neck and kept pressing. I was trying to claw it with my talons while my prehensile tail made him unable to move.

The rest of the fight was a long struggle. Although my " Diamond Teeth" were level 2, I found it surprisingly hard to pierce the scales of that thing and go through the muscles. Fortunately, my talons found a softer target at the hips and inside the tights. I could make the beast bleed from there even if I didn't know how much damage I was giving it. After a long while, my talons hit the bones and the basilisk stopped struggling.

Once the muscles in his neck had become limb, biting down had become easier. Once I was sure I killed it, trembling, I rose up from its corpse. It was only now I realized that one of my wing had being hit but his petrification and for a few seconds, a sense of doom filled my heart. From one look, I knew I couldn't fly again with that wing!

But... as I was thinking this was over for me, my skin suddenly started to peel?!

" Experience points have reached the fixed amount. Small Lesser Cave Bat LV.1 have become Lv.2 "

" Experience points have reached the fixed amount. Small Lesser Cave Bat LV.2 have become Lv.3 "

" Every basic ability increased. Skill Proficiency Level Up Bonus received "

Skill Proficiency reached. Skill "Diamond teeth LV.2" has become "Diamond Teeth" LV.3"

Skill Proficiency reached. Skill "Diamond teeth LV.3" has become "Diamond Teeth" LV.4"

Skill Proficiency reached. Skill " Concentration LV. 1" has become "Concentration LV.2"

Skill Proficiency reached. Skill "Petrification Resistance LV. 1" has become "Petrification Resistance LV.2"

" Skill Points Received "

When it finally finished, I felt refreshed and I was no longer petrified! I started to flap my wings and fly, both astonished and excited!

So this world IS like a video game! I can level up! Darn, I wish I had being reborn as a human. Maybe I could have learned a hero class with magic then. But I guess I'm stuck as... what was it... ah right, a " small lesser cave bat " monster huh? "

Even if I had this depressing thought in mind, the fact I escaped a deadly crisis made me unable to feel down. I still decided it would be best to return to the cave and consider my next step. The cave felt almost welcoming now. The constant squeaking inside could have become annoying but somehow, my brain just accepted it.

When I arrived and finally settled on the roof of the cavern, I begin to think deeply. I decided that before going out again, I should either train the skills I already have or try to get new skills I didn't think off. When I was tired, I would stretch my wings and try to fly... sometimes while avoiding drops of guano falling down. This training gave me some good results!

Although I never had wings before but I knew two planes manoeuver I wanted to try: " Looping " and " Barrel Rolls ".

It took some practice but I finally were able to make both of them. Even though I wasn't able to do them yet with complete ease, this training improved both my " Flying " skill to LV.5 and " 3D Manoeuver " skill to LV.6 !

My "Echolocation" also progressed a lot for trying it constantly in the cave. And after counting the bats AND the stalagmites with both " Echolocation " and " Appraisal " for the fourth time (yes, I was that bored), I got a new skill!

" Skill Proficiency reached. Skill " Calculating Processing LV.1 " has become learned. "

What?! Really?! So I actually can become good at maths in this world? Darn, I wish I had this skill when I still had math classes! I can't see it being very useful as a bat though.

As I was lost in thought, the giant bat that I seeing before made a move. I felt compelled to follow it and didn't fought this instinct. I wasn't the only one as a group was forming behind it. As we left the cave, I tried to stay in the middle of the group. It felt safer this way. As I was looking at the giant bat that I deduced as the " alpha " of this colony, I noticed that he was way more quiet then the rest of us. Now that I had a closer look, it didn't look very healthy either. I wondered what " Appraisal" would tell me about our dear leader now that the skill had leveled up. I decided to give it a try:

" Sonic Bat "

Wait, a Sonic Bat?! Oooooh, that's why it's bigger than the rest. I wonder why it stay in the cave with the lesser cave bats though...

This " Sonic Bat" seemed to know where it was leading us. After a while we ended up meeting a strange looking deer. The antlers seemed sharp as blades and the deer looked strangely intimidating. I tried to identify it as we got closer:

" Elro Deer "

Before I could ask myself more questions, the deer started running away. It was too fast for most of us but our bat leader followed it. It seem we were able to track him as we try to catch up to him. Soon, he was waiting for us. To my surprise, it was munching one of the deer leg on the floor. He was even crunching the bones like they were nothing!

My echolocation told me the rest of the deer was just a bit further down the corridor in front of me. Soon, the rest of the flock went for its prey...

It wasn't dead yet but it was now stuck on the ground. Although it was clearly fearful of us, it was facing us with those huge antlers, like telling us to get closer if we dared. It was cornered against the wall which made the task harder. I tried to find the best angle to attack it… but there wasn't an easy way to do this. I came up with a plan though…

I flew above the deer, very close to the wall. The deer knew I was there but I was out of his reach. But since I wasn't doing anything else, the deer focused on the other bats around it. When it tried to get a bat who was targeting its leg, it lowered its head... Using this opportunity, I took a dive, aiming for the base of its neck!

However, I didn't expect the deer reflexes to be this good. Its sword-like antlers rose up and I almost got hit by them. Fortunately, my flying was good and I managed to dodge it but only by a hair! I was shivering as it had being a bit too close for comfort.

Oh shit! Note to myself: I still need to improve my flying!

As I landed on the deer back, I heard the mysterious voice speak again:

" Skill Proficiency reached. Skill " Evasion LV.1 " has become learned. "

YEESS! Awesome! Now, sorry Bambi but its feeding time for us!

I bitten the deer's neck as hard as I could. However, my plan backfired a bit as it try to slam me against the wall. Although it hurt a little, it wasn't able to completely crush me against the wall because of its antlers. It also cause his belly to become exposed and the other bats took the initiative to bite it as well. The deer fainted, completely defeated. As I started munching on it, I realized the taste was... ok. At least it wasn't bitter because of the poison. Unfortunately thought, there wasn't enough to fill everyone. I was pushed away as they started to almost fight among themselves. Considering how much meat was left, I just let them fight for it and flew away. Soon though, the sonic bat grasped our attention again with his weird... ability. It must have being a skill as all bats suddenly stopped fighting and went to his location. The hunt continued. They found other preys but this time, I just waited on the sideline. Once the beast was down, I would join the others to get my share. Each time, the Sonic Bat crippled the beast and took a chunk out of it, leaving the rest for the lesser bats like me to handle.

I used my " Echolocation " and " Appraisal " constantly during the hunt, making them evolve one more level! I decided to use them on our next target. Soon enough, I spotted giant rat. One of the bat ahead grabbed it and swallowed it whole but I could get the name of it:

" Elro Griem LV. 4 "

Oh? It show the levels now? That's awesome!

As we killed a six-legged wolf, the sonic bat screeched something and the more experimented bats seemed to have understand. I was full at that point so I looked at what they were doing. They actually put the wolf in pieces and instead of eating it, they flew back in the direction we came from. I finally understood: they were bringing it back to the cave.

Well that was a good hunt... But in the same time, that deer... I should be more careful from now on. I got cocky there.

As the sonic bat leaded the way, I tried to use Appraisal again:

" Elro Sonic Bat LV. 16 "

Level 16 ?! Well I'm not close to it... I'll need to train a lot more it seem... but the path for it seem so long!

I decided that instead of just sleeping the days off in the cave like most of the other bats, I would continue to hunt by myself. However, I would play it safe and only goes for low level targets with sneak attacks. Unfortunately, it also meant most of the creature I ate during my training were low level poisonous creature. On the plus side, it did build my poison resistance by quite a lot. I would only come back in the cave once I'm too tired to continue hunting.

The next few days went on like that and my level and skills had increase a few times. I began to realize I was a lot more agile then most of the other bats already. I figured that it was probably because of all my skills and flying practice. With the raise in level of " Appraisal ", I figured out that I had a Hit Points (HP), Magic Points (MP) and Stamina Points (SP) bars. I figured more also about the Elro Labyrinth I was into and the fact it joined two continents was amazing.

One day however... something great happened. I had just killed an " Elro Griem" rat creature by dropping from the ceiling stealthily when suddenly the mysterious voice spoke again:

" Condition Met. Title Assassin Received. "

" The effects of the Title Assassin : Skill " Stealth LV.1 " and " Shadow Magic LV.1 " received. "

" Stealth LV.1 " has unified into " Stealth LV. 4 "

When I heard that, my heart beat increased from the excitement. I used Appraisal on " Shadow Magic ":

" Low rank magic that controls shadows. The strength of spells depend of the level. LV. 1: Dark Shadow "

Wait, it's only a low rank magic? Well it's magic anyway so it's still cool. But how to I use it? There is no instruction!

I tried to use Dark Shadow but nothing happened. I was getting frustrated so I decided to eat my prey first and then fly up above to hang upside down. I tried to recall the video games I being playing but nothing managed to work to activate it.

GRRR! DARN IT! I died as a virgin, I should have become a wizard when reincarnated, why it didn't happen! Bah, whatever.

I looked at my HP bar. Even after sleeping, it never went back to its fullest in the recent days. I had hoped I would eventually get another level to restore it fully but after each level, it proven more difficult. Maybe it was because I most often attacked target with lower levels then me? I really wish I could cast healing magic. I shrugged:

Since I can't use magic, I won't be able to cast a healing spell. Something like "white magic" would have being -

Suddenly, I saw something from the corner of my eyes further down the corridor... By using my echolocation, I was surprised to see something who left me astonished: HUMANS!

None of them was speaking. They seemed focused on their surroundings. I could hear the faint noises of their armor and weapons from where I was. The two in the front were a lot younger, one with a torch and the other carrying a bow. If they weren't obviously so visibly ready to duke any monsters they see, I think I might have lost myself and fly in their direction. But fortunately, I didn't. I blinked, watching them getting closer for a moment... before deciding I should go back to the cave.

Urk, they would clearly attack me if I go to them. Better back down...

Unfortunately... flying away seemed to have given away my position. I heard a whistling sound but before I could do anything, an arrow literally pierced my right buttcheek!

Now panicking, I tried to ignore the pain and I flew faster, pushing myself to hide behind a corner... only to arrive in front of a giant snake! The shadow of death was near as I was trapped between a group of human and a giant snake. I knew that this could be over right now and this sort of life crisis made rise every hair of my panicked body

Swearing inwardly, the snake was fortunately surprised by my sudden appearance. He still tried to bite me but I managed to dodge it. I counterattacked by biting it behind its head!

" Skill Proficiency reached. Skill " Evasion LV. 1" has become "Evasion LV.2 "

" Skill Proficiency reached. Skill " Pain Resistance LV.1 " has become learned. "

That's great and all but I can't deal with you right now, you stupid snake!

The snake tried to go forward and hit me on the stone wall. I had to let go of my hold on it and flew back under cover while the human could probably see the giant snake who just appeared within their line of sight. I didn't stay to find out. I was flying akwardly because of the injury, the arrow made it harder to fly around. I finally managed to land on a large enough rock formation on the ceiling to hang on. The pain was intense but I removed the arrow from my body thanks to my tail. Unfortunately, it broke and the head of the arrow was still stuck in my flesh!

Ah great, just what I needed. Darn, my HP almost went all down from a single arrow!

I dropped the rest of the arrow and went back to hide in the cavern. I decided to take a nap to recover from this near-death experience. I don't know how much time I slept but it was an uneasy sleep as I had to sleep through the pain. When I woke up, I felt a bit groggy too, like I overslept. I was surprise to hear the mysterious voice told me:

" Skill Proficiency reached. Skill " Pain Resistance LV.8 " has become learned. " Pain Resistance LV.9 "

" Skill Proficiency reached. Skill " Automatic HP Recovery LV.1 " has become learned. "

Oh, THAT skill! It means I got something like "Regeneration" now? Well that's neat I suppose but I wonder if it will be enough if that arrowhead is still...

I winced from the pain. Yet, that arrowhead was still there alright. I was anxious but I decided to just stay here in the cave. I wasn't wasting SP if I was waiting to recover and if my guess was right, if my HP does go up, that arrowhead should be pushed out of my body eventually. Sure I was putting my hope on "videogames logic" but I would rather betting on that then thinking I could get a infection. Their not much else I could do anyway with my health almost all depleted. And to my relief, after a few minutes, my HP did go up! It was just a bit slow.

Darn, I need to remember the roads the human take to avoid them or to at least find the exit of this darn place! I wonder if their is a skill that could help me find that exit.

I felt the pain had lessen in my sleep as the skill " Pain Resistance " had rose up in levels but it was still painful. After confirming there was a skill named " Memory ", I decided to try to train it for now. After I took a few hours to recall memories from my previous life and trying to remember the paths I went in this maze, the mysterious voice spoke to me again:

" Skill Proficiency reached. Skill " Memory " has become learned. "

I was relief. Maybe this way, I would be able to make a mental map or something of this place. After what seemed like forever, I felt the arrowhead was getting slowly expelled from my wound. As I was finally able to remove it with my tail, I gained another skill!

" Skill Proficiency reached. Skill " Piercing Resistance LV.1 " has become learned. "

" Skill proficiency reached. Skill " Pain Resistance LV.9 " has become " Pain Nullify "

" Conditions met. Skill " Pain Alleviation LV.1 " has being derived from skill " Pain Nullify "

I sighed of relief now that this ordeal was over with. I didn't know you could gain the ability to resist pain but it was welcomed. I waited, again, that my HP went up. Now that the arrowhead was gone, it was going way faster then before. When it was at 3/4 of its maximum however, my SP was at 1/3 of its total. The hunting team just came back so I couldn't count on them as well. I decided to go see if the corpse of the snake was still here. It was a bit reckless, sure, but I had spent a lot of time in the cave to recover and really wanted to stretch my wings. Of course, I used my " Echolocation" all the way to be safe. I would even use it behind me to prevent surprise attacks.

As I arrived, I noticed that the humans had killed the snake. There was a spider monster right next to it, already who had already eated half of the snake. I never saw this monster before so I used my " Appraisal " skill on it. It was a " Small Taratect " and it was actually only one level higher than mine. Not only that but I was also coming from behind in its blind spot. I closed in carefully and crushed it in one bite. I didn't eat it though, the taste and texture was awful and I had the rest of the snake to eat anyway.

But then... as I spit out the spider body... Heavens decided to prove me it had a sick sense of humour:

" Experience points have reached the fixed amount. Small Lesser Cave Bat LV.5 have become Lv.7 "

" Experience points have reached the fixed amount. Small Lesser Cave Bat LV.6 have become Lv.8 "

WHAT ?! It's NOW that I'm actually gaining levels ?! When that I was so close to be full on HP ?! ARE YOU ****ING KIDDING ME ?!

I felt like this world was playing with my sanity. Not only the life as a monster was dangerous but I was feeling like the system isn't fair. If I didn't played videogames, I wouldn't have think of the " Appraisal " skill for example. I wondered if my other classmates were reincarnated here and would have as much luck.

I might have even eat one of them from all I know... Urk, let's not think about that possibility ever again.

I ate the rest of the snake, which of course tasted awful because of the poison and the decay. If it wasn't because I was starting to get really hungry, I might have changed my mind. After that, I decided to return to the cavern.

The days went like this... full of danger, eating awful stuff and just training to get stronger. I was wondering if I would be strong enough to challenge the bat leader of our cave one day... Or get to the surface. I didn't want to think that far ahead however. The only thing my gaming experience told me is that I could maybe serve a human master who would give me good food instead of what I had to eat here. But for that, I would probably need to become a lot stronger.

AUTHOR'S NOTE: I'm not sure what to say this time. I love this fanfic and plan to write a lot more since I'm having an easier time writing this fanfic then my other ones. A lot of stuff happened in RL however, I might not always be able to post new chapters this quickly.

EDIT: I found the online light novel that the manga was based off. I found out a few things that weren't explained in the manga and did some slight change because of it. In short:

1) He gained the " Automatic HP Recovery skill " because of his injuries instead of buying the skill off. Turns out each level don't give as much skills point then I thought they would give, at least for Kumo-chan it was only 20 skills point per level. Her advantages over humans are monster abilities, evolutions and how she can gain skills through experience with challenges more easily. Evolutions seem to give 100 skill points so I'm going to keep that for my own OC too.

2) I made the Night Vision be on the Small Cave Bat skill list but it was growing slower than its evolution.

3) He didn't get a " Throwing " skill. Replaced it with " Piercing Resistance " to reflect the challenge he faced.