Reborn As The Boss Monster Of A Low Level Dungeon

My name is David I started off with a decent start in life I guess.I was born into a family that was upper middle class,and they worked for a nearby adventure guild.No one in my family was an actual adventure though they all just worked customer service but surprisingly all the jobs at an adventure's guild paid well,but I wasn't like the rest of my family ever since I could remember all I wanted to do was become the world's most powerful SSS class adventure like in a fantasy novel I grew up reading as a bedtime story.My family were scared and worried about me when they heard my dream was to be an adventure because no one else in the family had been we all just worked common jobs at the guild being easy for us to get it having family already working there and being taught how to manage it's jobs since a young age assuming we'd just grow up to want to work there too I mean why not decent income and safe with plenty of opportunities to meet amazing people.The people that became adventures were all people that had a powerful awakening ability or even better were a God's chosen which were extremely rare every kingdom only has 1 to keep balance the gods would only choose 1 for every kingdom with them being the world's most talented adventures being SSS class talents with ridiculous stats far stronger then anyone else could dream of being.I remember ever since I was child I loved going to the guild with my parents and seeing all the adventures and hearing their stories and seeing how excited the newbie adventures were.They would earn merit the more guild missions they passed allowing them to rank up from E rank all the way up to A rank.To be S rank or higher you'd have to get evaluated by a god or goddess themselves at the church after becoming A rank.Ranking up wasn't as easy as it sounded though you couldn't just do a ridiculous amount of low level task to rank up to A rank you had to increasingly more dangerous tasks to rank up depending on your rank like a C rank would have to do 10 C rank missions to rank up to B rank with each mission being enough to threaten a normal C ranks live so only the ones that were actually strong enough to become a B rank would actually be B rank and so on since they couldn't just rely on luck to survive missions at their own rank.Ranking up was also actually extremely rare besides it being dangerous for most obvious if someone had the strength of a B rank and was E rank they would quickly rank up to B rank but talent was rare most adventures were E rank to C rank with C rank being kinda rare to but not in comparison to anyone B rank and above.Most adventures would team up into a squad to complete missions unless they were extremely simple and safe like gathering herbs on a hillside or something but to actually face monsters or dungeons they would always form a squad for safety to increase survival rate and success rate.You might be wondering why anyone would want to be an adventure especially if they are E rank and stuck doing tasks that are dangerous enough to kill them unless it's something like gathering herbs and the answer to that is surprising simple.Its the same reason anyone does a dangerous job the pay even for an E rank is crazy at least for those dangerous tasks but even doing something safe like gathering herbs is a decent payout since they would have to be in perfect condition and stored in a specific way to stay fresh those tasks were usually payed by nobles or alchemist or usually a noble for an alchemist with them needing herbs all the time for medicines making those tasks an important necessity for any kingdom.On top that any adventure above E rank were treated much better then common people with all adventures being treasured by kingdoms as an important source of power incase of war after all common soldiers couldn't compare to anything beyond E rank.I payed close attention to every adventurer's stories I heard I wanted to learn whatever I could from there experiences after all knowledge is power speaking of which that made adventures that were mages even more valuable as they were much more rare then a normal adventurer and much more knowledgeable usually being in the tops of each rank with their magic usually being more powerful then what common adventures could accomplish but of course there were some that struggled to learn magic and use it too also being low rank.Mages loved research though and knowing all they could they would often capture monsters and experiment on them which was really more like torture or they would raid dungeons to get mana Crystals from monster which were very expensive and valuable with them only dropping from monsters in dungeons and that was important for everyone to know because no one knew why and that drove mages crazy about them.The monsters in a dungeon were a little stronger than other monsters outside them think of them as being roughly 30 percent stronger then other monsters of the same type as them with dungeon boss monsters either being completely unique monsters on there own only being found in dungeons or being 100 percent stronger then monsters of there species if they were also found outside which is why dungeons were so deadly even if you managed to beat monsters the same rank as you.Boss monsters from dungeons would also be E rank to SSS rank but even the weakest E rank boss monsters could defeat the entirety of the other monsters in their dungeons so if a dungeon was E rank and had maybe 10 E rank monsters not including the boss monster the boss monster could fight all 10 of those monsters at once and still would win 100 percent of the time.Usually adventures wouldn't enter a boss room and would just collect the mana crystals from the common dungeon monsters unless they rest before the fight,were fully stocked up on potions and weapons,or were trying to rank up and needed to clear the dungeon as part of one of their 10 rank equivalent tasks.Mana Crystals could be used to instantly recharge a portion of a mages mana with E rank mana Crystals being able to fill charge an E rank mages mana with a single crystal which normally takes about 3 days to fully recharge without taking any and that counts for mages of any rank they'd just naturally recharge in about 3 days no matter the difference in mana from other mages because that was just their natural recharge rate that they absorbed mana from the world in.Monsters that could use magic were different though being even more rare then mages they seemed to recharge in just a day meaning monsters likely absorbed mana much faster then mages.Mana crystals were also used to revive precious herbs that died once picked or to permanently enhance the amount of mana a mage has but it was pretty wasteful to do that.It would take 10 E rank mana crystals to increase an E rank mages mana by 25 percent and unless they were close to being F rank even after doing it 4 times to they would still just be an E rank 90 percent of the time the difference in mana a mage has in each rank is ridiculous.I often wondered where monsters came from because many say they just appeared one day they weren't always here it use to be peaceful without monsters but no matter who you asked no one seemed to know why monsters suddenly appeared.As valuable as mages were sometimes it was detrimental to have them in your party because sure there attacks were usually on par with normal adventures full power skills they ran out of mana fast from them which meant the party gained less money from dungeons having to use mana crystals to charge the mages mana back up instead of selling them and some monsters were just immune to low grade magic or resistant or immune to magic all together.Usually a party had to pay a mage to join them since they were valued as heavy hitters or split most the loot between them and the rest the party too giving the mages a higher percentage meaning sometimes mages were just refused a spot in a party all together even when they offered to join.The more I heard from mages and adventures the more I couldn't help but think maybe being a mage or adventurer isn't quite as great as I thought but when I remembered how everyone treated them like heroes and my family always bowing to them respecting them I knew no matter what I still wanted to be one it didn't matter I would never bow to anyone no matter who or what they were no matter what I'd surpass them all because that's my dream to be the strongest.The more and more I talked to my family about being an adventurer the more they had to give in eventually agreeing to let me become one after the awakening ceremony where I could see what special talent or abilities I would get meaning it pretty much decided what your specialty would be if you'd be a tank, swordsman,mage,archer,or whatever it decided the future of all adventures and god's would choose there chosen ones at the ceremonies too even though right now every kingdom had one so there wouldn't be anymore for the time being.I was so excited at the idea of actually starting the path to achieving my dream I often couldn't fall asleep at night id replay all the stories the adventures had told me at the guild Id constantly think of all the monsters I heard about and there strengths and weaknesses and most of all I would think of what I'd be chosen as what my specialty might be.To past the time til the day I got to go to the awakening ceremony I started a writing a notebook filled with everything I had learned pictures of all the herbs I knew about and there effects and all the monsters I knew and their strengths and weaknesses so I could prepare myself for the day I fought them almost like an adventurer guide book that I'm gonna go back and fill with my own thoughts and experiences once I become an adventurer.I thought of how funny it would be for it to become a kingdoms treasure or something one day when I achieved my dream maybe my hopes were high insanely so knowing I'd probably never make it to even C rank I wouldn't stop trying even if it killed me after I got chosen even if I make it to A rank one day and none of the god's deem me strong enough to become an A rank or stronger I'd keep trying.I woke up one day early in the morning so excited I couldn't stop shaking as I went with my parents to the guild and saw all the adventures again I told them tomorrow was my awakening ceremony and listened to the stories of theirs these were people I looked up to wanting to be like everyday the people I wanted to surpass.We all celebrated that night having forged a bond with them over the years and the next day they all attended my awakening ceremony in the kingdom my heart couldn't stop racing as I saw a royal guard and royal mage step out of a carriage and walk onto a stage with a small crystal ball made of an S rank monsters mana crystal.Everyone gathered around them taking turn placing their hands on the ball as it lit up revealing to the mage there potential and speciality.Eventually it was my turn and I clumsily staggered up to the crystal ball my legs shaking in excitement I had the biggest smile on my face as I placed my hand on the ball I probably looked like an idiot with my smile but I Didn't care.The magic ball started lighting up at first growing brighter and brighter til it was far brighter then anyone else's before me and the royal mage and guard let out a gasp but then it started to emit a low humming sound a shake violently as it kept getting brighter and brighter.The sky grew dark and stormy looking over us even though there wasn't a single drop or rain in sight the magic ball began to look like a miniature sun in my hand as we heard a loud voice that seemed to come from the sky itself."I am Cosmo the Demon Lord bringer of chaos slayer of gods the dark one that brought chaos into this world."Everyone's eyes widen and I heard the royal mage mutter that it was impossible that Cosmo disappeared the day the monsters appeared seemingly the reason for it all before all eyes turned onto me.It was like my hand was glued to the ball I couldn't let go I didn't understand what was happening before I saw 10 golden lights descend around me from the sky as lightning struck the earth with a deafening roar and I saw every kingdoms chosen ones all 10 standing where the golden light had fallen dazed and confused at how they got there.Then suddenly we heard multiple voices one again this time from the god's as the screamed something in unison to there chosen one something that terrified me as they screamed,"kill him."Just like that without even a moment of hesitation the 10 launched at me faster then anyone else could follow launching attacks so powerful the ground around me seemed to open up into a never ending pit but just as there attacks landed with another deafening roar erupting a giant explosion like a thousand nukes going off on a single place at once a golden dome surrounding the blast protection everyone else clearly from the gods themselves.The eruption faded and in the center of it where I stood there was another figure one who blocked the force for me that kept me alive.....he was standing there smiling at me with eyes that seemed to be the abyss themselves without a scratch on him.I couldn't will myself to move no matter how hard I tried my body refuse before he placed a hand on my chest and I could hear the gods screaming once more in unison,"No" as time seemed to pause around me a light engulfing the two of us as he said so calmly in a tone that seemed to have been a whisper but was somehow loud enough for everyone to hear,"I Demon Lord Cosmo chose you child as my sole heir."A loud deafening boom erupted from my chest where he placed his hand sending a shockwave through the crowd knocking everyone back as it continued to travel throughout the entirety of the world and a roar sounded from us as suddenly he was gone and the pressure holding everyone back seemed to vanish as the light faded away leaving the crowd tense and silent as they looked on just to find nothing but smoke.