Momonga starts to cast a few spells; it seems more buff than anything.
"[Lesser Strength], [False Data: Mana], [False Data: Life], [Resist Weakening], [Shield Wall], [Greater Magic seal], [Greater Teleportation]." Momonga casted these defensive spells in under a minute which was quite fast.
'I think that covers the basics, [Lesser Strength] Increases one's strength even if by a tiny bit. [False Data: Mana & False Data: Life] gives false data for MP and HP if [Mana Essence] or [Life Essence] is used. [Resist Weakening] is a spell that prevents someone from being weakened by an abnormal spell. And finally, [Shield Wall] creates an invisible shield around a target, which is me. Oh! And [Greater Magic Seal] combined with [Greater Teleportation] so that I can activate it in case I need a quick escape by saying [Greater Magic Seal: Release].'
Momonga moves his hand toward the door, ready to enter. But instead, the door opens independently, revealing the boss room, which was to Momonga's predictions and is why he took such precautions. Flashes of light start to bounce off the walls, and the crackle of fire can be heard as blue flamed torches light and illuminate a blue haze across the entire room. What stands in the middle is a gigantic skeleton knight, which Momonga almost mistook for a Death Knight, but this one is bigger.
'Alright then! Let's see what you can do!'
Momonga moves into the room, prepared for the battle to come. But right when his foot hits the floor, the gigantic skeleton moves immediately, summoning a skeleton war-horse alongside him.
"I guess I can presume you are a skeleton-knight then, let's see what you can handle. You will be my experiment! [Penetrate Magic: Acid Arrow]" As Momonga casts the spell, a green arrow fires out of his hand, hitting the skeleton knight. However, It doesn't seem to do much damage, which Momonga wasn't shocked about.
'So! It seems that it has some slight resistance to magic, though It is still nothing more than a brute guarding a room of no importance; even with its great size, this will be easy.'
Momonga gets his footing again, and he instantly starts a volley of spells.
"[Silence], [Shockwave], [Fireball]" Momonga cast three spells in a short amount of time. The first spell [Silence] was to eliminate all sounds in the area for some time. Next, [Shockwave] is an invisible wave through the air. It's said to be strong enough to crush plate mail. And finally [Fireball] a ball of flames fired directly toward the Skeleton Knight. It was meant to exploit the critical elemental weakness of the undead, which was Fire and Holy magic.
As the shockwave traveled toward the undead knight, It seemed to do nothing to it, indicating that it had more than just slight magical resistance. This was confirmed when Fireball hit the undead knight, which did practically nothing to it.
'Interesting, so it seems that I didn't give the undead knight enough credit. It has a more magical resistance than I first perceived. I'll assume its resistances are close to or comparable to the skeletal dragon, which is resistant to 6th tier magic and below, so I'll jump to 7th tier magic or above.
"Even though your magic resistance may keep you alive, your death is inevitable," Momonga said, awaiting the skeleton knight's next move. However, his words were met with a quick charge by the skeleton war-horse. But Momonga reacted in a quick haste attempting to divert the war-horse's path.
"[Dragon Lightning]" Momonga casts a lightning spell that forms a singular dragon that shoots into the skeleton war-horse. However, its resistance wasn't as strong as the skeleton knight, and it turned to dust instantly. Although this sent the skeleton knight into a pit of rage, it seemed that the skeleton knight was somehow boosted.
'What? A rage boost? Could it be that he might be part of a barbarian class?'
In an instant, the skeleton knight was upon Momonga. It slashed its sword with quick haste.
"[Greater Magic Seal: Release]," Momonga released his seal, which teleported him back, allowing him to dodge the incoming attack.
'Alright, I think this is enough experimenting; this fight is honestly starting to annoy me.'
"Time to end this... [Chain Dragon Lightning]," Momonga cast a spell which formed massive chains of lightning in his hand, which he shot forth. From it, a dragon formed, which quickly pierced the undead knight, destroying it entirely.
Momonga let out a slight sigh at his disappointment in that fight.
'Well... I did get good information out of that fight, at least. I can use my spells without limitations, although my mana consumption is still the same as in YGGDRASIL. Still, there are slight differences, such as me no longer having a user interface for the spells. But this brings up another matter; since there was a boss on this structure, the only obvious conclusion is that I was transported into a dungeon. If so, where could Nazarick have been transported? After I escape this place, my first few objectives would be testing out the Staff of Ainz Ooal Gown, then searching for the Great Tomb of Nazarick.'
Momonga started to walk around a bit more, exploring the boss room he had just conquered. He eventually noticed that the skeleton knight and skeleton war-hose both dropped what seemed to be a crystal. He picked both crystals up and opened a luminescent purple portal. He then stashed both crystals inside, storing them deep in his inventory for later research purposes as he saw them as monster drops.
'Well, I can presume that the crystals are monster drops. So there are still some game mechanics from YGGDRASIL or any other basic MMORPG. Hopefully, this will become useful at a later date.'
Momonga stored this information deep in his mind, keeping a mental note. Then, he looked around a bit more and spotted a newly opened door; he quickly headed toward it. Peeking his head through, he looked to the right and left. Looking to the right, he saw a dead end. Although he saw a long hallway to the left, he logically took that one.
Momonga's footsteps make an ongoing sound down the dark hallway and quickly pass by, taking twenty minutes. This makes him a bit wary since it's been eerily silent since he's left the boss room. He hasn't even come across the occasional low-level skeleton. Even though it makes him a bit wary, he's pretty calm. However, that might be because of his undead nature and that he still has his buff spells activated, which he cast before the boss room. Plus, he can sense undead naturally so that they wouldn't get a jump on him.
A few more minutes pass as he travels down this hallway, and he starts to hear a noise. As it seems a massive hoard of monsters grows ever-so-closer, he starts to count them fifty? A hundred? After a few moments, he realized that it was impossible to count them all at this moment.
'That's a lot of monsters, and this must mean that there's another boss, meaning the previous one was a mini-boss which makes more sense because of the mini-bosses weak nature. However, I don't want to deal with these monsters, so I'll have to end this quickly, and I know just the spell.'
"[Maximize Magic: Thunderball]," Momonga said as a gigantic thunderball formed in his hands. He pointed it towards the incoming horde. As he let go of the thunderball, it flew with great speed. It caused the monsters to scream in pain as it collided, and half of them turned into dust. The other half had multiple body parts burned to a crisp as they lay down in defeat and later died from the injuries.
Momonga walked past the dead horde, picking up their crystals, which he stored deep in his inventory. He immensely enjoyed gaining new items, hinting toward his collector's instinct. However, after a few minutes passed, he decided to resume his travels through the hallways. He eventually came across another door. It had a similar design to the last door, but this time around, he was prepared, so he immediately reached toward the door. In which it started to open by itself. He noticed this and waited for it to open once it did, he walked through, leading him into another large circular room.
'Another boss room, perhaps?'
Although, right when Momonga thought it was a boss room, a noise in the corner of the room confirmed it.