Theory#6: Demerzel is an AI.
Asimov's escape devastated Sumeragi since he was the only known successful test subject in Project Gunvolt at the time. With Sumeragi's connections, they may have gotten ahold of his body. Using said corpse, they could have taken Asimov's memories, personality and Azure Striker to place them in an AI construct. This is possible when thinking about the Butterfly Effect.
A century after the events of Azure Striker Gunvolt, Sumeragi managed to locate the remains of Asimov's body. There was dried blood stains at Firmament on Copen's revolver. Unfortunately, even with filtration gas masks, the lingering scent of death was repugnant. Sumeragi decided to send a different clean up crew later on.
In the meantime, they had what they needed. Asimov's Septimosome: The Azure Striker. This Septima was the first ever to appear, claimed to hold supremacy over all other Sevenths abilities. By some amazing opportunity, some of the scientists managed to uncover recordings of Asimov's personality and visual footage of the experimentation he underwent.
This allowed them to create an AI-construct of Asimov's personality. It was then named Demerzel, who originally was a humanoid robot that aided the Emperor of The Galaxy in Isaac Asimov's book "Foundation". Therefore, this was deemed fitting, as the construct could not find out its name origin, or past actions. Shortly after completing his rise within Sumeragi, Demerzel went through his files.
He had access to every file in order to over Sumeragi's operation. On this particular night, Demerzel was going through files regarding Sumeragi's enemies. One of which being a particular Copen Kamizono. He was deemed a threat after attacking Zonda, one of the Sumeragi Seven and worker in the Adept Hunter Unit.
The boy was found at Firmament as well, when he eliminated Elise. Records showed that his younger twin sister held the Muse Septima. Which was the only known Septima to ever be capable of tracking Adepts or boosting other Septimas. Demerzel put in a request to have Mytyl's brain placed in a machine.
After Mytyl was taken for the last time from the sanatorium wher she resided, the girl's brain was removed. It was placed within a jar to be studied so Septima matches and implants would be easier. Her body was incinerated shortly after within the Biochem Plant. Ever since, The Luminous Avenger swore vengance upon Sumeragi and justice for his sister.
Demerzel, however, planned to make sure that Copen would never be able to exact his revenge.
"Blade, inform the scientific department that preparations have been made to build the Butterfly Effect." Demerzel ordered.
"Yes sir." Blade confirmed as she bowed before leaving the room.
Demerzel folded his arms with a smirk on his face.
"Finally, everything is going according to plan. Soon, not even the Adept Slayer will be able to erase me." Demerzel grinned.
During the building process of the Butterfly Effect, an AI construct of Mytyl's personality was created as well. This was necessary so the researchers could identify any issues within the machinery. Once the machine was built, it underwent a few weeks of testing before being moved to Sumeragi's Secret Bunker 2.
Once everything settled down after he took down the Falcons and Demerzel, Copen was looking into some research with Blade.
"IX, I found something you need to see." Blade announced.
"What is it?" Copen queried as he walked over.
"Sumeragi got ahold of Demerzel and Mytyl's old bodies. Somehow they used this to make AI constructs of them. Look at this code I found." Blade answered.
Copen looked at the data for a moment before reaching a conclusion.
"It seems they did a brain scan. Based on the data for Demerzel, they scanned the remnants of his brain. Combined with a three dimensional build of how his brain looked before and the camera footage, they managed to recreate his personality. It was so lifelike, it's a shame I couldn't use it to bring Mytyl back." Copen commented.
"Boss..." Lola squeaked sadly.
After destroying the Butterfly Effect, Copen regreted leaving the sanatorium now more than ever. He would've destroyed Joule within an instant if he was given the chance. At least Asimov was the one to do it. Or, so it seemed.
Somehow, by reasons unknown, Joule was revived, as were Gunvolt and Lumen. The fighting continued until Joule fused with his sister. He believed this "tainted Mytyl". His pure, perfect, innocent sister, unaware of the dangers faced by Adepts such as herself.
She was completely unknown to the outside world. However, Sumeragi knew the power that Mytyl possessed and desired to use her as a weapon of destruction and chaos. The harm that was caused by Mytyl's Septima couldn't be overlooked. Many Adepts were harmed, captured, even killed because of the Muse sonar.
Copen claimed this was another show of how Sumeragi acted. They showed themselves to be a honest company with intentions to help. In reality, this company participated in many dangerous ventures. One of which was using his sister's Septima to harm other Adepts.
He wasn't complaining, it eliminated the concern of needing to wipe out some Adepts. But, it increased the risk of coming across others. Other Adepts that could possibly pose a worse threat than normal, if their Septima was enhanced with a Glaive. Some nights when Copen had too much coffee or stayed up past a certain time, he felt his thoughts weren't his own.
One such thought being his own father was against him. His research is what allowed Sumeragi to enhance Septimas. He felt this was especially true since somehow Sumeragi managed to get ahold of Mytyl's Septima, possibly from it being brought to S-FIT. This caused Copen to feel as if he were fighting his own family. But this fact had never hit closer to home until he destroyed Mytyl. That night, Copen sat in silence, pondering about the monster he'd become, rather than Adepts.