Physical transformation doesn't drastically change one's intelligence, but it does cause some changes.
She might not become a mature woman while retaining an 8-year-old's intellect. She would grow up a bit and learn a few more things.
After her [DARKNESS] transformation, the teenage Eve understood a few things.
Tearju liked Kaito.
Eve needed to help Tearju pursue Kaito.
So, she showed off Tearju's best parts, because she thought Kaito would like them.
In fact...
Kaito did like them!!!
This sudden, wonderful display made Kaito's heart pound like a King's Engine. Blood rushed to one area to ensure maximum supply!
"Eve, no, don't do that! Close the wormhole!"
Even though Tearju was a biologist, she knew what this was.
'Come to think of it, why wasn't Kaito coming to help!!'
"Mama, don't be scared~ Kaito-nii really likes Mama, so Mama just needs to be a bit bolder!"
"Th-this isn't a matter of being bold!!"
'Huh? Why did Eve suddenly sound... like she was a few years older?'
'Also, she knew more, and her personality had completely changed!'
Tearju's face was so red it looked like it would drip...
Oh no, it was sweat dripping from her forehead due to excessive shyness, steam rising from her head, her whole body burning up.
"Cough, Eve, you..."
"I know! Kaito-nii also wants to show Mama your best parts, right? I can help!"
The wormhole opened.
Kaito could have defended, but he chose not to, watching Eve's actions with wide eyes.
A wormhole appeared in front of Tearju. A large shadow cast upon her face. Tearju's eyes went wide.
Eve hopped over, grabbed the large shadow, and presented it to Tearju.
"Mama, look! Isn't this great! It's super strong!!!"
"E-Eve... wh-why can you..."
"Hmm? Mama, Eve knows a lot, a lot of things now! I don't know why, it's like I suddenly learned a lot."
"C-could you let go..."
"Hmm? Why, Mama?"
Eve held it in her hands, then rubbed her cheek against it affectionately, seeming to like it and not wanting to give it back.
By the way, was Eve a bit yandere at the moment?
"Kaito-nii, Mama doesn't seem to like it, so can I..."
"Wait!!!"
Tearju stopped her, even reaching out to take it back, pulling Eve's hand away.
But Eve didn't let go; she held onto the other end, treating it like a treasure.
"Kaito, what's wrong with Eve now!? Did you modify something incorrectly!?"
"Well... cough, I didn't change anything. I just fixed the berserk state caused by the [DARKNESS] transformation. Maybe... this is just the personality change that comes with it?"
"Th-then fix that personality change too!!"
"Well... doing that might take days or nights. I'm afraid I might mess up her original personality."
Kaito, enduring the pain, explained with a complex expression, feeling troubled.
This really couldn't be fixed.
Even if it could, he wouldn't.
Yeah!
Unfortunately, good things never last.
As Eve was trying to play with it, the wormhole suddenly disappeared.
Eve's body returned to its original form. She stood there blankly, blinking in a daze.
"Oh? Mama? Kaito-nii?"
"Eve?"
Tearju's hands were suddenly empty, and her body had also returned to normal. Although a large area of fabric was missing, she was more concerned about Eve's condition.
"Mama, what are you doing?"
Not only had her personality changed back, but her intelligence and speech pattern had also reverted.
Eve looked curiously at Tearju and Kaito. Seeing Kaito, she hopped over and leaped into his arms.
"Kaito-nii, did you come to take me out to play~~~"
'Uhhh...'
"Yes!"
Acting as if nothing had happened, Kaito smiled and stroked Eve's golden hair.
Half an hour later...
Tearju changed into different clothes, watching Eve as if she were some terrifying creature, keeping her distance.
Fortunately, Eve had indeed completely returned to normal, with no changes.
Later, for some reason, Eve quietly fell asleep in Kaito's arms, sleeping very soundly.
"Ka-Kaito... Eve earlier..."
Tearju, still shaken and suppressing her embarrassment, cautiously walked over and pointed at Eve to ask.
She desperately wanted to know what had happened to Eve.
"Well, it's likely that your original organization implanted a program for transformation and combat enhancement before Eve became a bio-weapon. That's why she turned into that stronger form earlier."
"Oh? I-is that so? But now she's..."
"Naturally, transformations have a duration. It's like an overclock state. Activating it doubles strength but also increases consumption. So, after some time, she returns to normal and needs rest to replenish spent stamina and mental energy."
Kaito gave an easy-to-understand explanation. Tearju nodded seriously.
She glanced again at the sleeping Eve, a relieved smile appearing on her face.
'Oh no, I would never get married now...'
'Wait, I never really wanted to get married anyway?'
"Um... th-today's events... can you not tell anyone?"
"Hehe, I understand. I won't say anything."
"Ye-yes... and also... well..."
"What is it?"
"I-it's just..."
"It's just?"