Sonja is a fictional character from the Underworld series of films. This character is the daughter of the vampire elder Viktor, introduced by flashback, in Underworld. Red Sonja, the She-Devil with a Sword, is a fictional character who first appeared in Conan the Barbarian #23 (Marvel Comics).
tetralogy (plural tetralogies) 1  A set of four works of art that are connected, and that can be seen either as a single work or as four individual works. They are commonly found in literature, film, or video games. ( 2 medicine) A combination of four symptoms.
Tetralogy of Fallot (TOF) is a common defect in which obstruction to the flow of blood from the heart to the lungs causes low oxygen levels in the blood. Open heart surgery to correct the heart defect is the only treatment that gives long-term survival.