|Subject of the United Kingdom of the 19th Century.|
|Nation or Planet of Origin|
|Base of Operations|
|Brown - Now Red|
Biologically modified human with superhuman strength, durability and mental abilities; having achieved apparent immortality.
Genius level intelligence with skills as a biologist, geneticist and evolutionist.
|Uncanny X-Men #221 (Sept. 1987)|
|Chris Claremont & Marc Silvestri|
Nathaniel Essex was a biologist in 19th Century Victorian England who developed advanced theories on biology and human evolution. A geneticist of unparalleled genius, he foresaw the coming mutations that would transform mankind. His unorthodox experiments resulted in his ouster from the Royal Society, and his wife to shun him.
Rejection by his peers and spouse led his alliance with the immortal mutant Apocalypse, who had lived since the times of ancient Egypt. To better serve his nefarious efforts Apocalypse transformed Essex into the superhuman and ageless being known as Mr. Sinister.