Just how strong is Grayfia Lucifuge?
A damn good question that tons of stray devils and folks from the underworld haven't been able to explain in detail to Rei.
All the young crimson devil knows right now is that Grayfia has nothing to envy from the 4 Satans when it comes to strength.
'So this is it... the power of an ultimate class?' thought Rei, as a dense demonic energy superior to his own clashed against his aura.
There was no intention of domination in the supernatural energy Grayfia was emitting, but she was applying just enough force to suppress him.
Kind of like an adult restraining a kid having a tantrum.
Seeing this, Rei's facial expression behind his gas mask showed no panic whatsoever.
However, he knew it now.
The gap between him and an ultimate class wasn't small.
Objectively, Rei estimated his chances of victory as slim against such a dangerous opponent.
Yet, an amused glint slowly formed in the young man's golden eyes.
A reaction that slightly surprised Grayfia.
'Why does he seem happy?'
A question she wouldn't get an explicit answer to from Rei.
Yet, this answer would impact both individuals' worldview.
Unknown to the strongest queen, Rei remembered a scene between him and Gorou.
A moment describing exactly the current situation.
…
"What can you do against a guy who's basically stronger than you?... Run."
That was the first answer Gorou had given Rei during a casual conversation between them, after a hunt.
Back then, there had been slight hiccups during the hunt because the opponent was very cunning and careful.
Yet, he ended up dying because of the huge difference in strength between him and the hunter duo.
However, a question came to the young man's mind after watching Gorou crush all the stray devil's tricks thanks to overwhelming force.
'What if it was me? How could I get out of this facing the master?'
At that moment, Rei had unconsciously become aware of a dangerous element during combat.
Rei wanted to know how to escape a situation as desperate as the one the stray devil experienced at Gorou's hands.
Maybe he had sensed Rei's dissatisfaction because of the atmosphere surrounding him.
Gorou let out a tired sigh because of the delicate future lesson he was about to explain to Rei.
"Listen to me carefully, Rei..."
It took about ten minutes of explanations, which Rei could mentally summarize like this:
If your opponent is faster than you, you'll set a trap for him and prevent him from escaping it.
On the other hand, if the opponent is stronger than you magically or physically, or even both... then you have to escape his grip and play for time using guerrilla-type methods.
When the enemy is exhausted or lacks resources to fight, then try to finish him off quickly to avoid nasty surprises.
There's also a case where the opponent is smarter than you.
He was advised to cut off all means for him to execute his plan and make him unable to act.
Of course, pure force is one way to achieve this goal.
Finally, what if the opponent combines all three cases (fast, strong, and smart)?
Gorou just said one sentence to help him in this last hypothetical situation.
"Rei... become a monster."
At that precise moment, Gorou's words didn't come from nowhere, but from a fictional character from his first life: Garou, from the OPM universe.
He wanted to make Rei understand the idea that adaptation can solve any unforeseen situation.
It would all depend on the young devil's flexibility during the confrontation.
After all, demonic energy has no real limit beyond the user's control and imagination.
…
'Back then, I didn't understand the term "monster" that master had mentioned, but now...'
Rei finally got it.
This answer, in his mind, is also the way to have a chance against the seemingly invincible opponent in front of him.
That's why he rushed toward Grayfia without the slightest shadow of hesitation, despite the crushing power displayed by the demonic servant.
A bold act from Grayfia's point of view, since the difference in strength is clear between them.
'Is he arrogant?'
This idea naturally appeared in Grayfia's mind, but it didn't take long to disappear quickly.
Why?
Rei's speed suddenly increased explosively, after reaching a close distance to her.
"Weird..." Grayfia slightly frowned at the strangeness of the situation before her.
'How did he manage to increase his speed so considerably?'
She was able to block the attack using a shield created with pure demonic energy, but she lost sight of Rei for a brief moment.
A troubling situation, apart from another element she noticed while facing the masked young man.
'His demonic energy...'
Using demonic energy to enhance physical abilities isn't rare in devil society, but the abilities Rei demonstrated are abnormal.
If Grayfia could explain it simply, Rei went from the speed of a high class to that of an ultimate class (low), without explanation or apparent cost.
She didn't perceive any demonic energy being used.
Worse yet, he had even become stronger.
"Unlike your appearance, you seem very talkative," he said, diving his gaze toward Grayfia behind the energy shield.
At Rei's remark, the maid's indifferent face didn't change for an instant.
Yet, the young man could discern slight anger in her eyes.
The Path of Sacrifice.
That's the name of the main magic Rei had imagined without Gorou's advice, because he knew the latter would reject the idea.
As its name suggests, it increases Rei's strength for a self-inflicted cost, or simply a sacrifice.
The cost varies according to the importance Rei places on the sacrificial element or what is consumed by the power of destruction during the use of demonic energy.
Of course, he can't sacrifice something he doesn't have or doesn't belong to him, and it must have a real permanent impact in his life.
As for sacrificing stray devils? He has no real attachment to them (loot), so he only gets minimal gain because of weak emotional damage.
However, Rei does it because he considers that minimal gain is still a plus, whether it's weak or almost null.
As for possible recovery of the sacrificed thing?
There's no way back.
Once the power of destruction consumes an element that's part of Rei or his loot, there's no recovery.
The object is lost forever.
Why didn't he make this ability temporary like a Super Saiyan? It's an element caused by the nature of the Bael clan's destruction energy.
It can only destroy and not create.
Using pure demonic energy simply made this magic unstable, since it's based on the very nature of destruction energy and quantum mechanics theories.
What theory? Nothing really gets erased from existence.
As a certain 18th-century scientist would say: Nothing is lost, nothing is created, everything is transformed.
After all: E = mc².
Rei's magic is, in a way... recycling.
'I... I don't remember that night anymore... why did I receive this weapon? No... it's not important right now.'
Rei had sacrificed a precious memory: the night when his master had talked with him heart to heart and had given him his chainsaw sword as a birthday gift.
Author's note: I know this chapter contains too many explanations, but it's necessary for the conclusion of #####.
Of course, I plan to write a bonus (motivate me with your feedback, whether it's comments, reviews... or stones, lol).