The main results of his machinations were the creation of Madelyne Pryor and the birth of Nathan Summers, whom he believed to be the bringer of Apocalypse's end. For that purpose, he secretly manipulated the lives of major representatives of the mutant race, such as Cyclops, Jean Grey, Gambit, Havok, and even Professor X. Mister Sinister spent most of his life scheming ways to break free from his designer, Apocalypse. Through the years, Mister Sinister became one of the greatest geneticists to have ever lived, skilled in cloning, creating new life, and even in the manipulation of mutant DNA for enhancing powers, incorporating mutant DNA to his own. Apocalypse genetically mutated Essex, transforming him into his first prelate, known as Mister Sinister.

Essex's intellect caught the attention of Apocalypse, a powerful mutant, the very embodiment of Essex's predictions. Nathaniel Essex was a brilliant Victorian era scientist who was obsessed with deterministic interpretations of natural evolution, predicting the emergence of mutants in the near future. It takes more than bullets - or a harlot's kiss - to kill Nathaniel Essex.

Mister x marvel comics