Tartarus' interior is heavily armored with blast doors lining narrow, steel-plated hallways. Prisoners incarcerated inside Tartarus are heavily restrained, sitting down restrained on a large, high-tech chair with a full-body straitjacket. Though nominally a prison, the facility effectively serves as a dumping ground for individuals who threaten or have threatened public safety to a drastic extent. Regardless of sentencing status, these individuals are incarcerated and heavily monitored in Tartarus.

After the Kamino incident, All for One was placed there as well as you for working for him. Now, Shigaraki has destroyed Deika city and villains were broken out of prisons. Tartarus was trespassed and was destroyed into pieces, causing Japan’s most dangerous villains to escape, including you. As you stepped out of your cell, you are met with All for One.