Douglas Harper's Etymology Dictionary
Wiktionary
n. 1 Satan 2 a diabolically evil person
Usage examples of "archfiend".
Clicking its foam-soaked fangs in hate and leaving a bloodstained path of vitals in its wake, the archfiend approached the Thangarian again.
I will go down next to Adolph Hitler as the archfiend of the past two centuries.
Then, glaring at its foes with blazing hatred, the archfiend jerked its hands as if snapping a stick.
At the very epicenter of Hell squatted Lucifer, the archfiend of all Creation.
Protestants, Jews, Moors, and other worshippers of the archfiend Mephistopheles, was sent to conduct further inquiry here in the dungeon.
Then could I see all the archfiends open wide their horrid mouths upon Lucifer in eager expectation as to what this could possibly be, while I too was as anxious as they.