Range of mana manipulation is not infinite.
The further Rei tried to control it, the `fuzzier` his control become.
That uncertainty follows probability distribution function.
'Mana is tightly connected to probabilities.'
Currently, plausible distance for Rei was about 10 meters from his head.
By a bit of experimenting and geometry, he determined that whatever is giving him mana senses is placed just under his brain.
Under prefrontal cortex to be more exact.
If he tries to manipulate mana further, the difference between expected and reality is about 1%.
At 25 meters that discrepancy becomes more than 10%.
For example, if he wanted to move D1 mana at a distance of 25 meters from him, by 10 centimeters, it might move by anywhere from 9 to 11 centimeters instead.
His senses becomes 1% inaccurate at about 100 meters.
But as he trains, everything becomes better.
His mana organ, which he decided to call mana core, is constantly upgrading and evolving.
Rei also developed a very important technique, sixth senses.
The principle is pretty simple, create dots of material mana spaced out by some distance.
Any movement in that area will be detected by his mana senses.
But despite being easy in principle, execution is difficult.
In just 1x1x1 meter cube, by spacing those mana dots at 10 centimeter from each other, the total amount of dots is 1000.
And he needs to track and support their existence.
By using that technique, his brain is constantly at work, and energy spendature of his organism growth with each dot.
So for the past few days, Rei was optimizing everything he can about it.
Form at which dots are placed is very important.
For example, by placing those dots at non-constant distances, in a pattern, one higher than the other.
It not only reduced the pressure on him, but also made his senses get more information.
That alone gave him ability to detect even flying needle, if it's only flies in a straight line of course.
Another important one was decreasing density the further it is from him.
At the distance of 10 meters, each dot is at the minimum of 0.5 meters from any other.
Decreasing the size of dots is also an option, but it requires too much of his brain power.
Currently the dots are about half a centimeter each.
He even planned the future of his six senses.
An autonomous AI system, to track and optimize it is the highest priority.
He also needs to develop an energy generation system.
Currently his ATP reserves are being used to power the work of mana core.
But if his theories are correct, mana is just an energy and can be used instead.
He will need to know more about mana core to truly make any decisions, so he will need to ask his mother for `experiment rats` in the future.
'But I also found a signs of my mana core storing, or may be even generating some amount of energy, which is pretty interesting.'
Anyway, currently he uses weakened six senses in his day to day life, and will only use them at full power while fighting.
As the benefit, it trains both his brain and mana core, which makes him better with each passing second.
-------------------
The banket was grand.
Main hall was full of people.
Tons of food was served at hundreds of tables.
Music played; calm and soothing.
Many high status nobles talked, building connections and drinking expensive alcohol.
Outside the mansion was a sparing ground, where many young geniuses spared, showing their strength.
'They are pretty strong. But are those really geniuses of out century?.. Disappointing.' Rei only looked at them for a few seconds.
"Ohh, miss Rose, it's a pleasure to see you!" One fat noble came closer to him and his mother.
'His fake smile can't be more obvious. Disgusting.' It was not just Rei who thought that, but Rose as well.
Other people also started looking in their direction.
But their gazes were on Rei, who was walking and showed emotions that he shouldn't have.
He looked like some sort of monster to them.
"Pleasure is all mine, mister... Richard." She visibly struggled to remember his name.
Besides noble stood a boy, around 4 or 5 years old.
Fairly handsome, but with a belly, just like his father's.
And opposite to what you may think, they were dukes.
Nobles with status second to only royalty itself.
"Haha, miss Rose is too polite. I don't want to waste your time, so let's get straight to the point."
Despite trying to stay calm, Richards expression showed fear. It was a well known fact that Rose can be... quick-tempered.
"I'm listening."
"...So, miss Rose should know that other two empires still hold a grudge against our.
It is very important for Solaris Empire to stay united."
'How cliche.' Rei was a big fan of novels in his previous life, so he can see some situations coming from kilometers away.
Fat duke paused for a bit, his nerves giving in.
'I might die.' He was scared for his dear life.
"So?" Rose nudged him to continue with a small smile.
"Umm, well... my son, Viliam, is a very talented youth...
Sterling family wants to officially propose marriage alliance to Kuroda family.
Heirs of Your dear daughter with my son will be outstanding!"
He finally got the courage to say what was on his mind, completely forgetting about Kuroda family's curse.
And that was his mistake.
Rei's eyes turned cold as ice as he looked at a fat man and his son in front of him.
And that scared them.
Viliam even almost pissed his pants... Nope, he definitely did. How pathetic.
People in the hall tried to suppress their laugh, but failed at the end.
Especially other young heirs and masters. They were dying from such a comical scene.
Back to the duo, their instincts warned them of danger, but as dukes they were proud...
"Disgusting pets." Rei's voice was cold, emotionless.
'What... what is this?.. Why am I scared? I am clearly stronger than this child.' Richard thought were a mess, he was extremely confused.
And Rose? She was entertained.
Although angry at such a proposition, she decided to leave it to Rei.
And of course people saw everything.
Despite it being Mei's birthday banket, appearance of Rei changed everything.
Being a high status nobles, they knew about the curse.
So how did a male heir appeared in that crazy family?
He was also walking and speaking as if it was nothing.
The danger he emitted was absurd.
And worst of all?
The feeling of being seen.
It was unpleasant feeling, like they were being constantly surveyed.
And all of that from the child who was not even a year old?
That by itself was unbelievable.
They even ignored his handsomeness as it was a common trait of Kuroda family members.
"Y-you, BASTARD!" Viliam, being an arrogant young master, wasn't able to bear the shame of wetting his pants from just Rei's gaze, in front of everyone including Mei.
And so, he attacked.
He was only slightly bigger then Rei, but had close to none muscle mass.
Usually, noble heirs start their training at age of four, so his and Rei's experience was the same in this world.
Richard, his father, tried to stop him, but Rose blocked any of his attempts.
Just as Viliam's fist was about to connect with Rei's face, he moved.
A slap was all it took.
In the very next moment Viliam was on the ground, his face imprinted in marble floor.
A silence filled the hall as Rei cleaned his hand with a napkin and threw it on top of Viliam's head.
And then he just stood there, as if nothing happened.
'S-so cool,' at that moment, young ladies found their idol.
The news of 1 year old boy beating a 5 years old duke son with a slap will definitely spread far.
The absurdity of situation was very entertaining for public.
After all, were there ever such an absurd 1 year old?
-------------------
There was no more marriage proposes after this.
To Mei that is, Rei received more then 10 of them.
He didn't straight up declined them, but didn't accepted either.
Rei's standards were absurdly high.
Every maid in the mansion was a world class beauty, and only some of the proposed girls were at this level.
'Which is already strange, it's like a world is trying to give them to me.
Their parents are not that gorgeous, which means that they were born like this near the time of my rebirth.
A world scale anomaly.'
"Fufu, what gigolo am I rising?" Rose's mood grew. She was proud of her son.
"That was to be expected, just look at my handsome face!" He put his fingers in his hair, fully showing his beauty to the world.
Thankfully, no one saw his shamelessness, as they were in a private room, together with Mei.
"Hehe, brother is handsome!" Mei shouted enthusiastically.
"At least you understand me!" Rei patted her head in a sign of approval.
"H-hey! I agree as well!" Rose, their mother shouted with a pout.
Rei looked at her strangely, but still patted her as well.
She even pushed her head against his hand.
'I swear I can feel her purring! Is she a cat? And who is a child here???'
What a bizarre situation! I'm definitely not jealous!
-------------------
No one else was willing to spare with Rei.
Younger children knew that they had no chance, while older ones had a lot of pride.
What will they gain by winning against a literal baby?
And so, the party quickly concluded.