Personal Info:
Real Name: Lloyd Bloch
Also Known As: Moonstone, Byron Becton
Place Of Birth: Frederick, Colorado
First Appearance: Captain America Vol.1 #169 (1974) Modern Age Villain
Known Associates: Secret Empire
Group Affiliation: Former agent of the Secret Empire, The Corporation, Quentin Harderman, Committee to Regain America's Principles
Base Of Operations: Mobile
Grudges: Captain America, Falcon and the Avengers
Creators: Steve Englehart, Mike Friedrich and Sal Buscema
Gallery: Click
Enhanced Abilities: Nefarius has vast super human strength, agility, speed, durability and endurance.
Ionic Energy: Nefarius was mutated into a being of Ionic energy similar to the likes of Wonder Man and Count Nefaria.
As a thief, Lloyd Bloch stole a Kree Lifegem from a science installation and found himself bonded to the artefact. Developing superhuman powers and strength from the Lifegem, Bloch outfitted himself as a super-villain and dubbed himself Moonstone. As Moonstone, Bloch became an operative of the Secret Empire who helped him hone his powers and abilities.
Bloch's operated as an agent of the Secret Empire in several of their plans until they were defeated and he was jailed for his crimes
While imprisoned, he received support and guidance from psychiatrist Karla Sofen. Although, unbeknownst to him, Sofen was merely manipulating his emotions with her eyes set on acquiring the moonstone from which he derived his powers. After convincing him to relinquish the moonstone, Sofen stole it and bonded to it herself, leaving him powerless and imprisoned.
While in prison, Bloch's befriended a fellow inmate who by chance had discovered how to emulate the experiment which gave Count Nefaria his ionic powers. Moonstone underwent the process himself and became much more powerful than he had been before and, wearing a costume similar to Nefaria's, he renamed himself Nefarius and set out to gain revenge on Sofen.
Nefarius at Marvel Database
Nefarius at Comic Vine