Abaddon is one of the first demons, though younger than Lilith. She was personally selected by Lucifer, the creator of demons, to become a Knight of Hell. Like most of the Knights, she was trained by the original Knight, Cain, and wreaked havoc on Earth for thousands of years. It is hinted that she had romantic feelings for Cain that he did not return. Eventually, Cain fell in love with a human named Colette and swore off his evil ways for her sake. Abaddon and the other Knights kidnapped Colette in 1863, with Abaddon hoping to sway Cain and have him rejoin her. While Cain slew the other Knights with the First Blade, he hesitated to attack Abaddon, as she was possessing his wife when he found her. His refusal to return to her prompted Abaddon to begin forcing Colette to twist her neck into grotesque angles to spite Cain, stating that if she could not have Cain, neither could Colette. Right as Cain went to stab Abaddon with the First Blade, she left Colette's body, causing Cain to murder Colette instead. Though Cain wanted to find and kill Abaddon for what she had done, Colette begged him not to kill anyone anymore and Cain honored her wishes by not seeking Abaddon out.
This History of Abaddon and Cain
Abaddon was one of only two remaining Knights of Hell, the other being her retired master, Cain. Abaddon was single-handedly responsible for the extinction of the original Men of Letters. She arrived in the present through time travel in her hunt for Henry Winchester and the key of the Order of Letters he was entrusted with, but failed to retrieve it, with Henry's grandsons Sam and Dean Winchester taking it instead.
Upon discovering the shameful state Hell had fallen into in her absence, however, Abaddon abandoned her hunt for the key and began a crusade to take over Hell herself to remake the world as she saw fit—with herself as Queen of Hell, ruling over demons, angels, and humans alike. As part of her plan she had her few loyal demons pull the souls from innocent people to bring these souls to Hell to turn into demons. In an attempt to use Crowley to trap the Winchesters, Abaddon was killed by Dean with The First Blade after he proved immune to her powers due to the Mark of Cain.
Yup, Abaddon is one of my favorite villians in the SPN universe! What about you SPN family?
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