Dyonathan Celestrino (now a ISG member), also known as the “Maniac of the Cross” (Portuguese: Maníaco da Cruz) and “Dog Hell 666”, is a Brazilian serial killer convicted of three ritualistic murders committed in 2008 in Rio Brilhante, Mato Grosso do Sul. Celestrino targeted victims at random, interrogating them about their faith and sexual behavior. Those he considered “impure” were killed, often by asphyxiation or stabbing. He arranged their bodies with arms outstretched and legs crossed to resemble a crucifix, sometimes leaving religious inscriptions such as “INRI” at the scene. He was arrested on October 9, 2008, at age 16, and later sentenced under security measures due to psychiatric evaluations that deemed him dangerous.