Shouts and screams erupted from within the fortress walls.
They were the voices of allies—soldiers of the Aiwood Kingdom Army.
"Enemies!"
"The Foreign Tribes have breached the fortress!"
"Close the gate! At this rate... Gyaaaaaaaaaaaaaaaargh!?"
"“““““Ooooooooooooooooooooooh!”””””"
The Foreign Tribes swarmed into the courtyard.
A hundred, then two hundred... the number of intruders inside the fortress continued to swell rapidly.
The tribesmen moved with preternatural speed. Their natural agility rivaled the enhancements mages gained through magic, allowing them to glide into the fortress with terrifying grace.
"This is... bad. At this rate, the fortress will fall!"
Atop the ramparts, Rest gritted his teeth and shouted.
If the situation didn't change, the enemy would soon overrun the entire interior. Allied soldiers desperately tried to heave the gate shut, but the fierce interference from the Foreign Tribes kept them at bay.
For the moment, Rest activated his magic to seal the entrance.
"[Earth Shield]!"
A wall of solid earth rose at the fortress entrance.
Though the breach was now plugged, obstructing the enemy's entry, the Foreign Tribes immediately began hacking at the barrier to tear it down.
"I need it thicker... or better yet, I could drop heavy stones...!"
If he summoned massive boulders with magic, he could crush the invaders at the gate while sealing the entrance simultaneously. It was a perfect two-for-one solution.
Rest prepared to cast the spell, but a chill of pure killing intent suddenly brushed against the back of his neck.
"——!?"
"Hup!"
A sharp blade whistled through the air, aimed straight for Rest’s throat.
Rest instantly bolstered his physical abilities with magic and leaped away from the spot. When he landed and looked back, he found a figure wielding a dull-edged blade standing exactly where he had been a moment before.
(A human... no, is that really a human?)
A small figure stood there, face hidden deep beneath a hood. Judging by the slight build, it looked like a boy, though there was no telling if he was even human. Perhaps he was a member of the Foreign Tribes in disguise.
"That was dangerous... Who are you?"
"Die... Sorcerer...!"
"——!?"
The intruder kicked off the stone floor and lunged, blade in hand.
He was fast. Even without the visible telltales of magic, he moved as if bolstered by [Physical Enhancement] or [Accelerator] spells.
"[Super Accelerator]!"
Rest invoked a high-level enhancement spell to evade the strike. Simultaneously, he triggered his counterattack. Multiple spheres of crackling electricity manifested around him and surged toward the intruder.
"[Thunderball]!"
"Kh...!"
However, the intruder twisted his body mid-air, weaving through the [Thunderball]s. His kinetic vision and physical flexibility were nothing short of astonishing; it was a feat of agility that should have been impossible to pull off at that range.
"Die...!"
"Ugh...!"
Having evaded the magic, the intruder pressed his advantage, swinging the blade once more. Rest tried to leap back again, but his heel struck stone—a wall. At some point, he had been cornered.
Perhaps he had been momentarily shaken by how easily his [Thunderball]s were dodged. Whatever the reason, he wouldn't be able to conjure a new wall in time to protect himself now.
"No choice then...!"
Rest steeled himself and stepped forward, driving his body toward the incoming blade.
"What...!?"
"Guh...!"
He blocked the strike with his upper arm. The sharp tip of the blade bit deep into his flesh. Even so, as long as it didn't pierce a vital organ, he could [Heal] the damage with magic.
Enduring the sharp pain, Rest reached out and seized the intruder's wrist.
"[Thunder Shock]!"
"Gwaaaaaaaaaaaaaaaaah...!?"
The intruder's body convulsed violently as a massive surge of electricity tore through him. His grip on the blade failed, and he collapsed onto the rampart on his back.
"Ah... gu..."
"That really hurt... I wish I could find a way to turn off my nerves with magic."
Rest yanked the blade from his arm and focused on the wound. By drawing upon his [Infinite Mana], he could regenerate an entire limb from scratch if he had to. The deep gash closed and vanished instantly.
"Sorry... it looks like you were the one destined to die today."
He manifested a [Wind Blade], intending to deliver a swift decapitation.
"...Ugh......"
"Ah...?"
However, he froze just before releasing the [Wind Cutter].
The hood of the fallen intruder had slipped off during the struggle. Revealed beneath the yellow-brown fabric was the face of an innocent boy. A single horn protruded from his forehead, confirming his identity as one of the Ogre-kin among the Foreign Tribes.
"A child...?"
Back in Japan, he would have been no older than a primary schooler.
Rest hesitated to deliver the finishing blow. On a battlefield, there was supposed to be no distinction between adults and children. He had thought he was prepared for the reality of war, but seeing the face of a [Child Soldier] in the flesh made his resolve crumble.
"You... Foreign Tribe scum!"
"Medic! Call a medic!"
While Rest hesitated, the chaos around him only intensified. The [Earth Shield] he had created was finally breached, and a fresh wave of enemy reinforcements began pouring into the fortress.
"I have to do this..."
Rest used his magic to [Bind] the boy, wrapping him in multiple layers of dense earth ropes. No matter how high the boy's physical capabilities were, he wouldn't be breaking out of those.
"First, I'll seal the gate for good... [Earthball]!"
A single sphere of earth appeared in the air.
At first, it was small, but it rapidly began to swell, bloating until it transformed into a massive boulder over ten meters in diameter.
"Crush them."
"Gyaah...!"
He released the massive weight directly over the exterior of the gate. The tribesmen who had just broken the [Earth Shield] and were preparing to charge in were flattened instantly, letting out muffled screams.
The [Earthball] shattered upon impact, collapsing into a small mountain of debris that completely plugged the gate.
"Now, all that's left is to clear out the ones who already made it inside...!"
Turning his attention back to the interior of the fortress, Rest dove back into the fray to support the defending soldiers.