Marvel's resident expert geneticist. Dr. Nathaniel Essex's long history of experimenting on mutants is as horrifying as his origin and self-made mutations. In his quest for a perfect mutant race, Essex procures his subjects by any means, earning him a name as evil as his intent - Mister Sinister.

Scenario 1: (OC or crush) discovers she's pregnant! But she discovers she's not the only one who's interested in the baby. Mister Sinister has plans of his own for the baby.

Scenario 2: Mister Sinister has been collecting mutant DNA, and has taken Duck for a special purpose.

Scenario 3: Make your own.