Antichrist

1 :  one who denies or opposes Christ; specifically :  a great antagonist expected to fill the world with wickedness but to be conquered forever by Christ at his second coming

2 —used in an exaggerated way to describe a person regarded as a powerful and malevolent adversary ; usually used with the With time this contrast hardened into hacker iconography. Gates was the anti-Christ, a man whose corporate stranglehold on the software industry had left it awash in ugly products. — Robert Wright