Armed Dolls. This was a type of autonomous anti-Honkai weapon designed by Dr. Einstein of the Previous Era.
Although the entirety of the Mu continent was destroyed by the attack of the Ninth Herrscher, the Herrscher of Rock, and Dr. Einstein threw all the Armed Dolls into the Sea of Quanta through a portal, the manufacturing technology for Armed Dolls was still preserved.
Otto had told Ryn to destroy the power-depleted, dormant Armed Doll Kevin, but Durandal felt it was too much of a waste to destroy it directly. It could be kept, reactivated, and used as a training partner for the Valkyries.
"Durandal, not everyone is on the same level as you..."
"That's right... It's better to let such a dangerous thing remain dormant..."
Finally, under the strong condemnation of Rita and Otto, Durandal reluctantly handed Armed Doll Kevin over to Ryn.
However, since it was a product of the Previous Era, it should naturally be shown to someone from the Previous Era. So, Ryn took Armed Doll Kevin to find Fu Hua.
"Fu Hua, what do you think? Any ideas?"
"No, I have little expertise in scientific research. you should take it to Dr. Yiselian."
Fu Hua spread her hands, indicating that she was powerless. After all, if she could really handle Armed Dolls, then the Book of Cangxuan wouldn't still be dormant.
"Alright, then it's fine."
Ryn turned to leave with Armed Doll Kevin in his arms, but halfway there, he turned back.
"If I try to forcefully hack the Armed Doll, will it self-destruct?"
"No."
"Oh... What if I just take it apart? Will it explode?"
"No."
"Oh."
Since it wouldn't explode, Ryn decided not to leave.
Ryn placed Armed Doll Kevin in Fu Hua's living room, then took out Cortana's terminal and placed it on Armed Doll Kevin's body.
"Your upgrade material. It's all yours."
"I'm so grateful you even remembered me," Cortana gave Ryn the middle finger, then merged with Armed Doll Kevin.
Three seconds later, Ryn suddenly felt his body being hollowed out as a large amount of Honkai energy was transferred to Cortana through their connection.
But soon, the Honkai energy was replenished from his link to the Imaginary Tree, only to be immediately drained again by Cortana.
Watching Ryn alternate between looking completely drained and being full of vigor, Fu Hua couldn't help but speak up.
"If you're sick, maybe you should see a doctor?"
"It's fine... I just feel like my body gets hollowed out sometimes."
"?"
With Cortana's declaration of "Done!", Armed Doll Kevin began to melt into a pool of liquid metal, which then re-forged itself into a small Cortana figure.
Fu Hua sighed, silently mourning the demise of the little Kevin doll for three seconds. Then, she and Ryn watched the newborn Cortana.
Cortana clenched her fists, feeling out her own strength. It was about 101% of the original Armed Doll, roughly one point zero one percent of Kevin's strength.
Although it was said to be one percent of Kevin's strength, Kevin could kill ten thousand Armed Doll Kevins with a single blast of Might of An-Utu. Strength isn't something that can be expressed by numbers alone.
"I never thought my day would come! Ada and Ai-chan, prepare to face my rule once again! Ahahaha!!" Cortana placed her hands on her hips and laughed wildly.
"What about your computing power? How much has it increased?" Ryn interrupted the arrogant Cortana, asking her the most crucial question.
"Uh..." Cortana deflated instantly, poking her fingers together and saying awkwardly to Ryn:
"How much computing power can the body of a single Armed Doll provide... It's not like it's a supercomputer cluster... Besides, I'm not a computational AI, I'm just a key..."
"Don't change the subject."
"If you really want to know... it's about this much..." Cortana raised her right hand, touching her thumb and index finger together, leaving only a tiny gap.
"????" Question marks filled Ryn's head, which tilted so far it nearly touched the ground. "You melted such a powerful Armed Doll, and your computing power increased by almost nothing?"
"You said it yourself, it's powerful in a fight... What does that have to do with computing power... Besides, I'm very powerful now!"
Cortana raised her hand, and the replica of the Greatsword of Shamash that the Armed Doll originally wielded—in its Shuhadaku of Uriel form—appeared in her hand.
"With a single swing now, I can burn this house and the surrounding several hundred meters to ashes!"
"And the consumption?"
"Um... the energy is linked to you... so the cost of this swing... hehe." Cortana stuck out her tongue, giving Ryn a look that told him to figure it out himself.
Because Cortana lacked the ability to automatically conserve Honkai energy, even the energy for her daily functions was drawn from Ryn, just like Oath of Judah.
To put it into perspective, for the same amount of energy consumed, Cortana could destroy an island with one sword strike, while Ryn could sink ten islands with a single slap...
"You're utterly useless! Spit the Armed Doll back out! I'd be better off letting Dr. Yiselian dismantle it!" Ryn grabbed Cortana by the neck and shook her vigorously.
"I can't help it! This thing isn't even made of Soulium! If you could get me a room-sized amount of Soulium, my computing power would surpass Ada's in an instant!"
"Get lost! If I had that much Soulium, I could make so many more Divine Keys! You think I'd let you waste it!"
"Then let's go rob Otto! He has a bunch of Soulium bodies. Even though the Soulium content in each body isn't very high, if we steal enough of them, we can definitely gather what we need!"
"You go ahead then."
Ryn gave Cortana a look as if she were an idiot, and Cortana scratched her head awkwardly.
If Cortana were to attack Schicksal HQ, it was uncertain whether she could steal Otto's Soulium, but she might be able to scrape a little off Durandal's Abyss Flower.
As Cortana and Ryn were staring at each other, Fu Hua interrupted them and asked Cortana, "Cortana, if it's just for daily maintenance, is the energy consumption low?"
"Yes, combat consumption is quite high, but the consumption for normal daily operations is almost negligible."
Fu Hua hesitated for a moment, then looked at Cortana and Ryn with determination in her eyes.
"Then... can Cortana help me change an Armed Doll's power supply to Honkai energy and link it to me?"
"Uh... I'd have to try first..."
Fu Hua nodded, then packed her bags overnight and asked Theresa for leave. She then borrowed Little Zi from Ryn and took the "bird plane" back to Mount Taixu.
The next morning, as Ryn opened his dorm door, he saw Fu Hua, covered in mud and holding a chubby little white doll—an Armed Doll.