Riezel knew he had been messing around in this world for over two months, and he was already tired of it.
What he wanted wasn't just to fight the powerful but to have adventures that would push him to the edge of death, something that would get his adrenaline rushing and fill him with excitement he had never felt before.
From that perspective, Riezel's first dimensional travel to the world of Danmachi was a perfect fit for him.
After all, Falna, which only allowed for level-ups through adventure and excelia, paired with Riezel, who loved adventure, wasn't afraid of danger, and liked to fight powerful opponents, was basically a power system made just for him.
If it weren't for his previous dealings with Ainz, where he wanted to learn as much Tier Magic as possible, Riezel would've already come to the Great Tomb of Nazarick, ready to dive headfirst into that den of dragons and tigers, instead of just bullying the weak natives of this world.
Now, after officially falling out with Ainz and becoming enemies, Riezel finally had the chance to visit the Great Tomb of Nazarick.
One could say that, even if nothing had happened with Lakyus and the others, once Riezel finished his business in the royal capital, he would still have immediately made his way to the Great Tomb of Nazarick.
Danger?
Danger was exactly what he wanted!
If it wasn't dangerous, how could he call it an adventure?
If he didn't take risks, how could he earn high-rank excelia?
If he didn't earn high-rank excelia, how could he level up?
For Riezel's current strength, the only way for him to level up was clearly to challenge the Great Tomb of Nazarick.
Ainz himself had already admitted it—Riezel's displayed strength had surpassed the maximum level of Level 100, proven by how he was able to fight and defeat multiple Level 100 NPCs at once, which was definitely not something an ordinary player could handle.
Unless the Dragon Emperor, the only one confirmed to have strength exceeding Level 100, reappeared, no one in this world could match Riezel in one-on-one combat.
Given that, if Riezel wanted an adventure and to earn high-rank excelia to level up, his only option was to challenge the Great Tomb of Nazarick.
"Maybe this time I'll die..."
Muttering to himself, Riezel stopped bothering with Ainz and charged straight toward the Great Tomb of Nazarick below.
"Damn it!"
In the throne room on the 10th Floor of the Great Tomb of Nazarick, both Ainz and all the heteromorphs present were filled with rage and murderous intent toward Riezel's actions.
"Demiurge!"
Ainz's ominous aura flared as he stood up from the throne, his fury evident as he gave orders.
"Get the resources needed for resurrection right now, and bring Shalltear and Albedo back to life!"
"Deploy personnel to all the floors as well, and activate all the defense systems!"
"We have to make sure that anyone who dares to invade the Great Tomb of Nazarick is permanently left here!"
"I'll make some preparations on my side as well, and if necessary, immediately use the 8th Floor and the World Items lying dormant in the treasury!"
Needless to say, Ainz was truly angry this time, no longer holding back and preparing to use the full resources of the Great Tomb of Nazarick and the full power of Ainz Ooal Gown to crush Riezel!
"All Floor Guardians and Area Guardians, deploy!"
At Ainz's command, the heteromorphs, brimming with murderous aura, roared in unison.
""YES!!!""
And so, the entire Great Tomb of Nazarick began to mobilize against a single enemy.
===
Just like that, Riezel's invasion of the Great Tomb of Nazarick began.
Since the 1st to 3rd Floors had already been destroyed by Fallen Down, Riezel directly landed on the 4th Floor, standing before a massive underground lake.
At the bottom of this underground lake lay a strategic-type golem, which was also the 4th Floor Guardian of the Great Tomb of Nazarick, known as 'Gargantua'.
However, because it lacked intelligence and was essentially just a giant siege machine, it didn't participate in any meetings or actions of the Floor Guardians.
It was understandable.
Not only was it not considered part of the Great Tomb of Nazarick's denizens, but it didn't even have subordinates—just an unintelligent golem, a tool.
If one were to judge purely by combat power, this enormous golem, Gargantua, would even surpass Shalltear, but unfortunately, Gargantua had no intellect, no sentience—it simply followed orders.
Because of this, among the intelligent Floor Guardians of the Great Tomb of Nazarick, Shalltear remained the strongest. If Gargantua had intelligence, it would definitely be the strongest Floor Guardian, not Shalltear.
Fortunately for Riezel, his arrival didn't disturb the golem in the slightest.
Gargantua needed a period of time to activate whenever it wanted to be used, which was why it was placed on the 4th Floor, giving it time to activate before the 1st to 3rd Floors were breached.
However, because Riezel had used the Super-Tier Magic, Fallen Down, to blow up the 1st to 3rd Floors of the Great Tomb of Nazarick, directly infiltrating the 4th Floor, there was simply no time to activate Gargantua.
As a result, Riezel ignored this floor and flew toward the 5th Floor.
Why not use teleportation?
It was simply because the Great Tomb of Nazarick had mechanisms in place to block teleportation, so if one wanted to move to a lower floor, they either had to use the pre-set teleportation gates or walk there the old-fashioned way.
Riezel was tempted to cast another Super-Tier Magic, blasting through a few more floors, but by now, Ainz had activated all the defense systems of the Great Tomb of Nazarick, making it impossible for him to easily use Super-Tier Magic to blow up Nazarick.
Even though Super-Tier Magic was powerful, it had one major flaw—it required a long preparation time. Furthermore, Super-Tier Magic also somewhat resembled special skills, as it could only be used a maximum of four times per day unless a cash item was used to cancel the preparation time and usage limit.
In other words, it was nearly impossible to use Super-Tier Magic effectively in actual combat without cash items.
Moreover, after entering the Great Tomb of Nazarick, Riezel found himself under a constant barrage of attacks—whether it was being swarmed by groups of undead or triggering thousands of traps, he couldn't find the time to use Super-Tier Magic.
For this reason, Riezel could only charge forward, with no way left to take shortcuts.
Luckily, Gargantua was still inactive, so no matter how many undead there were, they were no match for Riezel, who easily dealt with them.
As for the traps, Riezel could only think to himself that, in the face of Decomposition Magic, they were no more threatening than paper—not even a single one could touch his body.
Riezel simply wrapped himself in the crimson waves of Decomposition Magic, ignoring the thousands of magic traps attempting to strike him while cutting through the undead army blocking his path and invading the 5th Floor.
While the glacier zone on the 5th Floor was a tricky place for others, it didn't have much of an effect on Riezel. With Pioneer of the Sun in his possession, he was not only resistant to high temperatures but also to low ones. Perhaps the only obstacle on the 5th Floor was Cocytus and the large group of ice monsters he led, trying to stop him and keep him on this floor.
Regardless, once Riezel's body burst into flames, turning him into a small sun rising on the floor and melting all the snow and ice, the outcome became inevitable. Not only could the numerous ice monsters not stop him, but Cocytus also fell to his Sun Breathing, his body evaporating from its intense heat.
As a result, Riezel safely passed through the 5th Floor and entered the 6th Floor.
Riezel had to admit that the 6th Floor was definitely much more troublesome than the 5th Floor.
Not only was the 6th Floor filled with all kinds of magical beasts and even dragons with levels above 90, which could only be created by paying within the Great Tomb of Nazarick's administrative system, but with both Aura and Mare joining the fray, Riezel faced considerable resistance.
Of course, what made the 6th Floor troublesome was undoubtedly the existence of the twin Floor Guardians, Aura and Mare.
Aura was a group battle specialist NPC with beast tamer as her job class, who commanded numerous magical beasts and had a special skill to strengthen their power, which made Riezel feel as though he was being attacked by a vast army of enemies ranging from Level 6 to Level 7.
As for Mare, who was second only to Shalltear in strength among the Floor Guardians, with druid as his job class, not only could he use various support and healing magic, but he was also highly skilled in elemental magic, particularly in the earth attribute.
Needless to say, with Mare supporting Aura from the rear, the difficulty of the fight increased even further, causing Riezel to be held back on this floor and fight fiercely for almost an entire day and night.
Only after a grueling battle, one that felt as if it could tear the sky apart, did Riezel finally manage to exhaust and defeat the numerous magical beasts and the twin Floor Guardians.
"How... How could this happen...?"
"Is his stamina and magical energy infinite?!"
"How can a human fight for so long without feeling any fatigue?!"
Many heteromorphs watching the battle on the 6th Floor were left in disbelief.
Let alone them, even Ainz was the same.
Logically, even undead who didn't experience fatigue, didn't need food, and didn't need sleep should have had their vitality or magical energy drained after such an intense battle—they would have been unable to maintain their full combat power and would have been weakened to some extent.
Bizarrely, Riezel, supposedly human, showed no signs of this.
Not only did his magical energy never run out and his stamina never deplete, but his eyes continued to glow steadily, brighter than ever.
Was he really human?
He was more like a perpetual motion machine!
'Damn it! How could there be such a monster?!'
Ainz couldn't help but grumble inwardly as he watched Riezel already break into the 7th Floor.
Opposite the 5th Floor, the 7th Floor was a lava-filled zone that presented no real obstacles for Riezel.
In a high-temperature environment like this floor, forget about being affected—Riezel thrived instead, using Sun Breathing without restraint.
As if absorbing the heat from the entire floor, Hermit, known as the divine sword in the world of Demon Slayer, glowed with a bright red light, easily slicing through every devil's body, which had extremely high physical defense and fire resistance, ultimately killing Demiurge, who had been commanding them from behind.
Ultimately, Riezel made it through the 7th Floor much faster than the 6th Floor, taking only about an hour and a half to get through without any trouble, achieving the incredible feat of clearing the first seven floors of the Great Tomb of Nazarick all by himself.
Naturally, there were several reasons it had turned out like this.
One reason was that many of the traps in the Great Tomb of Nazarick were ineffective against Riezel, who was constantly surrounded by Decomposition Magic. As soon as they touched him, they disintegrated, rendering one of Nazarick's most important defensive systems useless.
Another reason was that with Shalltear and Albedo both fallen, not only had the Great Tomb of Nazarick lost its strongest Floor Guardian on the first three floors, but it had also lost the Guardian Overseer, who could lead all the Guardians, which made Nazarick's defensive power drop significantly.
Moreover, with Gargantua unable to be activated in time, Riezel could easily charge through the 4th Floor, which should have posed a huge challenge in a short time.
And the last reason was that Riezel was quite familiar with the original work and had some understanding of the Great Tomb of Nazarick, which gave him part of the strategy and countermeasures needed for success.
All of these reasons combined allowed him to clear the first seven floors with ease.
'It's you who's forcing me, Riezel Brynhart!'
Seeing Riezel about to step onto the 8th Floor, Ainz's gaze turned ruthless.