So this was the reason.
Realizing the truth, Izumi let out a small sigh and turned to Le Fay.
"Yeah, that's not a magic workshop at all. Looks like something big is buried under my house."
His eyes gleamed with curiosity.
"We'll dig it open and check it out."
This house wasn't something he bought.
It was something gifted by the system.
Which meant—of course—it wouldn't possibly be normal.
Le Fay blinked in confusion.
"Ehh… it's not a magic workshop? So I guessed wrong…?"
Izumi didn't bother answering. He walked straight into the yard, knelt down, and began sensing the mana running belowground.
A massive magic formula pulsed faintly in the depths—one that felt like a seal, tightly suppressing something.
Izumi grinned.
He projected a shovel into his hand.
"Alright. Excavation time."
Le Fay and Asia froze.
"E-Eh? We're… digging? Like… really digging?"
Even so, the two quickly recovered from the shock and rushed over.
Le Fay used magic to move aside entire layers of dirt.
Asia grabbed a shovel and did her best to match the pace.
Izumi could have punched the ground open in one go, but doing so would likely turn the entire house into a pile of rubble. So, painstaking manual labor it was.
After more than thirty minutes of digging—
A massive pit had formed. Dirt piled up like miniature mountains around them.
And at the bottom of the pit stood a colossal stone gate densely covered in countless glowing magic circles.
Mana from the air flowed continuously into the patterns, feeding them like a living creature.
"An… ancient ruin…?"
Le Fay's voice trembled with excitement.
"And the magic formations are incredible…! Izumi-sama, w-wait! Don't break anything yet! I need to record them first!"
Without warning, she pulled out a notebook from who-knows-where and began sketching frantically like an honor student desperate not to miss a single detail.
Izumi sighed.
The moment anything related to magic appeared, Le Fay instantly switched into scholar-mode.
He turned back to the stone door.
A sealed ruin, beneath a house in the middle of a Japanese city.
No matter how he looked at it, this wasn't normal.
If not for his overwhelming detection ability—and Le Fay's insane mana sense—they might never have noticed this place at all.
His abilities had recently ascended to the level of a Transcendent, although he still wasn't used to the power. Even so, these magic circles had almost fooled him.
Which meant their quality was absurdly high.
Meanwhile Le Fay was nearly drooling with excitement as she continued drawing.
Izumi finally snapped.
"…Hey, Le Fay?"
"Mmh?"
"Why aren't you using your smartphone?"
She froze.
Turned around stiffly.
"…Ah. Ha… haha… I completely forgot."
Face red, she closed the notebook and immediately switched to rapid-fire photography with her phone.
By now the sky was turning dark.
Once Le Fay finally finished documenting everything, Izumi nodded.
"Alright. Step back."
"Okay, Izumi-sama! But… how do you plan to open it? These magic circles are ancient—breaking even one will activate defensive arrays. Force won't work."
Izumi chuckled.
"If it's magic, I can break it."
A confident smirk surfaced.
He projected Rule Breaker—the multi-curse-shattering dagger—and thrust it straight at the center of the arrays.
Pshhk.
BOOM.
The moment the blade touched the formation, the entire array shattered like glass.
The collapse didn't stop there.
A chain reaction erupted, dozens upon dozens of circles cracking and dissolving.
Others activated violently, launching attacks at Izumi.
But he didn't flinch.
He simply punched every incoming spell to death.
Explosions echoed high above the house—so loud that half of Kuoh Town heard them.
The three factions still lingering nearby all turned their heads toward the blast.
And far across the world, in the deepest halls of the vampire progenitors—
The Third Primogenitor, a petite girl with gemstone-green hair, felt the ancient ward she had helped create shatter.
She grinned.
"Oh? Someone finally found it."
She lifted a foot.
"Then let the festivities begin."
With that, she vanished.
The First Primogenitor's camp reacted next.
Another figure launched toward Japan.
So did several chosen successors.
Meanwhile, Izumi finished clearing every last trap and seal.
One punch blew the stone gate to pieces.
Inside—
A vast underground chamber.
And at its center—
A massive coffin of pure ice.
Within it lay a small, beautiful girl with shimmering red hair, as if sleeping peacefully.
Le Fay gasped.
"An… an Akashic-type vampire…?! And what incredible mana…!"
She instantly recognized the aura.
There wasn't a single trace of humanity.
Only pure, overwhelming vampiric power.
Izumi stared silently.
He knew exactly who she was.
Avrora.
The Fourth Primogenitor from Strike the Blood.
Sleeping directly beneath his house.
Izumi felt his soul leave his body for a moment.
"…Seriously? Why the hell is she here…?"
The system might as well have put a ticking bomb under his bed.
He wanted to cry.
Was the world trying to kill him with surprise crossovers?