The poison of dark mages was closer to creating non-existent, imaginary poisons with the mage's power rather than ordinary poisons found in nature.
Outstanding dark mages often combined and fused multiple of these imaginary poisons to create even more complex and vicious poisons.
Naturally, the undead mage was also a mage of that level.
-To complete the multi-poison, you need to start with fifteen basic poisons.-
"..."
-First, mix three poisons...-
The undead mage was definitely saying something, but it wasn't registering in Yi-Han's mind.
That's how high the level of poison element magic was.
-...You heard it all! Try it!-
"...Poison, bloom and boil. The blooming poison is..."
Although he didn't understand even half of it, Yi-Han tried chanting the spell first due to the urgent situation.
Poisons appeared, gathered, and changed colors while swirling in the air.
-Shoot as soon as it's complete! There's no time!-
"...Move!"
The poison took shape and flew much faster than the one the undead mage had shot earlier.
The undead mage couldn't keep up with Yi-Han's bizarre elemental control.
While the undead mage practiced higher-level magic without bothering to learn such techniques, Yi-Han had trained rigorously.
-Excellent!-
However, the undead mage misunderstood Yi-Han's peculiar magical ability in a different way.
He judged that such movements were possible because he was an inherently outstanding mage.
With such high expectations, the undead mage was very disappointed when Yi-Han's multi-poison failed to completely melt the berserker's body and only burned the muscles.
Sizzle-
-Ah... What?! Why are you even doing dark magic if you're slow at undead summoning and can't handle poison!-
The undead mage stomped his foot in disbelief.
Judging by the fields of magic he handled, his ability to chant magic, and his elemental control, he seemed to be a more outstanding mage than himself, so why were there so many mistakes?
"I apologize."
Although it was incomplete, honestly, it was still remarkable to have succeeded to that extent in the current situation.
Objectively, it was a situation where he could get angry, but...
Yi-Han apologized.
He was already used to the unreasonable demands of crazy professors.
Instead, the one who got angry was Ogoldos.
"Don't apologize! Why should you apologize! You crazy undead bastard!"
-What did you say!?-
"I don't know how many hundreds of years old you are, but is it right to teach incorrectly and then get angry at a young mage! The principal wouldn't do that!"
-Wha... What...?-
The undead mage was confused.
Judging by the way they spoke, these two mages felt quite young.
Whoosh!
In the meantime, flames erupted in front.
The undead berserker spat out bodily fluids and ignited them through friction.
"..."
Yi-Han was shocked by the madness of setting himself on fire to drive away the cold. It was a brutal tactic that only the undead could do.
'He's coming!'
The undead berserker swung his burning body and pushed back the skeleton warriors once more.
His movements were still slow, but anyone could tell that he would soon break through and charge.
"Senior. Do you have any ideas!"
"Even if I did...!"
Ogoldos felt like his chest would burst from frustration.
He himself was only a second-year, so how could he come up with a clear solution?
The curse magic, bone element magic, and poison element magic he knew how to use were likely to be ineffective against that berserker.
Didn't that undead berserker show terrifying stamina in the earlier battle?
The barricade was broken, the cold element magic was destroyed, and it was difficult to restrain his steps with mediocre bone or poison magic...
'Summons... If I can somehow use summons to buy time...'
If Sharakan, who was left alone to target him, was ignored and he charged this way, there was no way to stop him.
They needed to place a sturdy summon in between.
Ogoldos, who was desperately racking his brain, suddenly thought of something and asked,
"Can't you reduce the number of skeleton warriors and combine them!?"
"Pardon?"
"I said, can't you reduce the number and combine them!"
Now was not the time to summon multiple weak summons.
Even if it was just one, they needed a summon that could somehow endure.
Usually, summons that were contracted and summoned couldn't be arbitrarily combined or fused by the mage, but Yi-Han's dark magic was a method where the mage directly summoned them.
If the number was reduced and combined, their power would increase and control would become easier.
"Return, and... Rise, warriors made of bones!"
Yi-Han swung his staff as his senior said for now.
The skeleton warriors collapsed and returned to their original reagent, bone fragments. Those bone fragments combined again and rose as a single skeleton warrior.
Because he poured in dozens of times more reagents than ordinary magic, the amount of mana used in the spell and the amount consumed for maintenance was enormous, but the result was clearly visible.
A skeleton warrior with a stiff and sturdy body, as if compressing over ten skeleton warriors, was born in front of them.
'It... It really worked?!'
Ogoldos was startled.
He had shouted in a hurry, but upon reflection, reducing the number and combining them wasn't an easy task.
Ogoldos also knew well what it meant to over-invest reagents and mana into a set magic.
Yet, that junior succeeded in a magic close to gambling, befitting his reputation as a genius. Just by looking at the size of the summoned skeleton warrior, it was evident that he had combined quite a lot.
Ogoldos let out a sigh of relief without realizing it.
"Thank goodness... Wait! If you could do this, why did you summon over ten and fight?"
Ogoldos couldn't understand.
If he could do this, shouldn't he have done it from the beginning?
The undead mage also seemed quite curious about that question and turned his gaze to Yi-Han.
"I forgot."
"What??"
"I summoned a lot while practicing and fought like that because I was distracted. I apologize!"
"..."
-...-
The undead mage and Ogoldos wanted to scream at him, asking if that was something to say, but they couldn't.
The berserker was charging.
Bang!
The berserker had taken all kinds of damage, from penetration to poison to cold to flames, but his strength was brutal.
The skeleton warrior blocking the passage creaked and was pushed back. Yi-Han swung his staff.
"Shoot forth!"
Along with Yi-Han's spell, bone fragments were fired from the skeleton warrior's torso.
It was a method possible because Yi-Han had directly assembled it, not a contracted relationship.
However, the berserker pushed the skeleton as if he didn't care even if bone fragments were embedded in him.
As creaking sounds continuously erupted, Yi-Han gritted his teeth and reinforced the skeleton.
"By Beavle's rule, mana, be emitted. Cold, be imbued! Poison, bloom and boil. The blooming poison is...!"
Yi-Han cast mana emission enchantment, which he learned from Professor Beavle, on the skeleton warrior's bone fragments and imbued them with cold and poison.
Amplified mana. Cold. Poison.
As these three elements collided, the skeleton warrior became unstable as if it would collapse at any moment. Yi-Han injected more mana and somehow performed emergency treatment.
As bone fragments mixed with poison and cold were continuously fired, the undead berserker also became impatient and drew up all the strength in his body to somehow overpower them.
Ogoldos suddenly thought of something and shouted,
"Wait, you said you know how to use the dark element! Why aren't you infusing dark elements!"
"...I forgot!"
"...Hurry up and do it, please!!!"
Unable to bring himself to get angry at a junior who learned too much magic, Ogoldos screamed again.
As the dark element was infused into the skeleton warrior, the skeleton's bones turned black, becoming sharper and sturdier.
"Shoot forth, shoot forth, shoot forth!"
Papapapak!
Bone fragments were embedded like buckshot into the berserker's already tattered body.
-Can I detonate it?-
"Pardon?"
-That skeleton, I mean!-
"Please do!"
When he asked for Yi-Han's permission, the undead mage nodded and drew up the mana he had barely recovered.
The gases imbued in the bone fragments reacted with the mana, causing a chain explosion reaction.
Kwakwakwakwakwang!
As the reinforced skeleton exploded, the undead mage shoved Yi-Han and Ogoldos into the room next to them. The air in the passage swirled madly due to the aftershock of the explosion.
Yi-Han was impressed by the undead mage's skill.
"I didn't expect it to be this powerful..."
-How much crazy mana did you pour in!!!-
The undead mage shouted and stared at Yi-Han.
He definitely didn't intend for it to be this powerful.
There were countless things to say, such as the situation in the outer passage, the secret to maintaining such a reinforced skeleton, and why he didn't stop him when he said he would detonate the skeleton, but the undead mage's first choice was Yi-Han's age.
-...You're not even twenty?!-
"Can't you tell by looking?"
Ogoldos replied sullenly.
-Do you know how many years I've been an undead?-
"...I, I don't know?"
-Just as you can't guess my age, naturally, I can't guess your ages either. You all look the same.-
The undead mage shook his head and lamented.
He thought he might be the chief mage of a kingdom because he used a variety of magic and had overflowing mana, but he turned out to be a greenhorn not even twenty years old.
Indeed, there were too many clumsy parts here and there.
-Wait, you're not even twenty, but how did you follow the multi-poison...-
Rumble!
As the sound of collapsing came from outside again, the undead mage slightly poked his head out.
-!!!-
Yi-Han also poked his head out and said,
"Senior. I have good news and bad news."
"Wha... What is it?"
"Thanks to that explosion earlier, the ceiling was blown away. It seems we can go up if we step on the debris."
"Re-really?! Wait. What's the bad news?"
-More undead berserkers are coming.-
"..."
Ogoldos could be certain of one thing about Yi-Han.
That junior had the worst sense of humor.
-How much mana do you have left?-
"I haven't consumed any."
-You haven't consumed any?-
"I said I haven't consumed any."
-...Wha... What... No. Okay. Then can you summon skeleton warriors again like before?-
"I used up all the bone fragments as reagents..."
"Ask for them! Aren't they here!"
Ogoldos shouted and placed a reagent pouch in Yi-Han's hand.
Yi-Han spoke with a slightly touched expression.
"Thank you for your help, both now and earlier."
"You call that help... Damn it. It's fine. Summon them quickly! Before they get close!"
-But that was just luck that it ended like that last time. If we do it again, I can't guarantee safety.-
"Of course it'll be dangerous to fight! But we can't not fight!"
Ogoldos shouted, dumbfounded by the undead mage's words.
However, the undead mage shook his head and replied.
-I'm talking about detonating the reinforced skeleton.-
"..."
"Can't we use it and avoid it like before?"
-I said we were just lucky last time. Can't you finely control the mana to match the detonation?-
"I tried it for the first time today, so how can I control it delicately?"
The undead mage clicked his tongue at the reasonable argument.
It was certainly a difficult statement to refute.
'Why is he not even twenty...'
Thud-
A rock suddenly flew in. It was a rock thrown by the berserker. The undead mage hurriedly pulled back his skull.
"...?"
When there was no attack after that, the undead mage poked his head out again.
The berserkers gathered in front of the ceiling debris were murmuring and pointed upward with their hands.
"What are they saying? An offer to surrender?"
To Yi-Han's question, the undead mage spoke as if it was hard to believe.
-They're telling us... to go up first...?-