Many attempts have been made throughout the series to create a Level 6, though only the Level 6 Shift Project has been sanctioned by Academy City. Despite all these efforts, there have still no successful attempts at creating a Level 6 esper.
List of known Level 6 Shift attempts
- Ability Body Crystal Project: Kihara Gensei's attempt at achieving Level 6. Using the crystallized esper essence of overloaded espers on a chosen esper, Gensei theorized that one can attain a Level 6. Exposing the crystal to overloaded espers with the same ability, and to another esper who has the same ability and can achieve higher levels of power when exposed to certain factors, one can cause an AIM Diffusion Field Resonance thereby causing the resonance to power-up the esper, allowing the achievement of a Level 6. It was later abandoned by Gensei, though his granddaughter, Therestina Kihara Lifeline tried to continue the experiment. She was foiled by Misaka Mikoto, Shirai Kuroko, Uiharu Kazari, and Saten Ruiko.
- Level 6 Shift Project: Gensei changed tactics and became a major proponent of the Level 6 Shift of Accelerator. According to Tree Diagram, only Accelerator can achieve Level 6. As such, it was later calculated that Accelerator can achieve Level 6 if he kills clones of Misaka Mikoto, known as Sisters, 20,000 times in battle. It was later foiled by Kamijou Touma, Misaka Mikoto, and the Sisters themselves, helping Touma defeat Accelerator and making Tree Diagram's calculations that Accelerator is the strongest esper look erroneous.
- Level 6 Shift attempt on Misaka Mikoto: Gensei once again attempted to create a Level 6, this time using Misaka Mikoto, though an unstable one unlike Accelerator. After a series of ruses and gambits, Gensei took over Shokuhou Misaki's Exterior, and invaded the Misaka Network via Misaka 10032 using Exterior, forcibly connecting the Misaka Network with Misaka Mikoto. Gensei was foiled by the combined efforts of Misaki (destroying her Exterior in the process, preventing Misaka Mikoto from continuously being connected to the Network), Sogiita Gunha, and Kamijou Touma, finally ending Gensei's quest to create a Level 6.
- Level 6 Shift attempt on Hishigata Hirumi: Isaac Rosenthal, an ancient spirit from the Rosenthal Family, a family that has tried to create the perfect golem, also known as God, or in science side terms: Level 6. He takes over the body of Hishigata Hirumi after she was resurrected by Esther Rosenthal using the spirit Taowu. He is later instructed by a self-proclaimed demon, that to create the perfect golem, a god, a soul will evolve slowly after it dies 10,000 times. Under the control of Hirumi's body, he manipulates her brother, Hishigata Mikihiko for this end: to create the perfect body and the perfect brain to create the perfect esper, a level 6. Hishigata later attains Misaka 10046, and takes from her the data needed to complete their formula as the Sister clones have experienced 10,031 deaths at the hands of Accelerator. Using Hirumi's body, Isaac inputs the formula into her body, making her body transform into a huge grotesque form.