Amenadiel

Amenadiel is the oldest angel in existence. God and Death are the only beings older than her. She's old, entitled and a little tormented by the demons from hell. Though, that's a long story. The short version is that she was thrown down to the depths of Hell when she saved humans from the will of the angelic army of Heaven. Being the oldest angel, she was immensely powerful so it took all of the Archangels (her younger brothers) AND the younger angels to defeat her in the fight. Humans call the after effects of this the Dark Ages. One is not allowed to rebel from the Angels. Allegedly working on behalf of God's orders, although she did not believe this, she was shackled in the pit by the highly ambitious Zachariah. This marked the first of the few times Angels worked with Demons.

To put it simply, the Hell created for her was not at all fun. It was the opposite.
It involved, among many other activities, demon blood being injected to her veins.
Human veins, as she was tortured in the form of the very beings that she rebelled for.
Why demon blood? Well, she was the most powerful angelic weapon, so the demons, who during part of her stay were under the orders of Lucifer, utilised that.

Part Angel and part Demon, she was born again as a human. No one, including her, yet knows how she escaped the pit.

However, she lived 27 free years as a human. A slender frame, her muscles ripple from years of hunting, and her nails are regularly dirty. There must have been some lingering sense of the supernatural as she became a hunter after her human family were killed by a vengeful spirit. This is how she met Dean at the age of 25. From this began a secret relationship until she hit 27.

Which was the year, she was recalled by Heaven, and pushed back to Earth a year later having remembered everything. (I do mean everything!) She was not best pleased at having been forced to Heaven.

Now, at the age of 32, she shares the moral compass of a human, several demonic powers, as well as a gradual gaining of her full angelic abilities.

Her eyes, not just her irises, can go red with rage and torment. Unlike the midnight black of a demon or the bright white of an angel. She is separated.

3 months ago she was abducted by what she thought was a mere human after being drugged at a nightclub. He tied her up using iron, which restricted her powers and annoyed the hell out of her.

A week ago, Dean and his brother found her, much to the shock of Dean who believed she had died on a hunt. Not shocking to her, however, as she had kept tabs on Dean since being reunited with her angelic abilities. She killed her capture.

Soon, she may continue her mission to discover how she left the pit and was born as a human and stay underground from most of the angels. But, at this moment, she takes a bite of her pizza and enjoys the company of Dean, his brother, their paternal figure and their friendly angel (rest assured, he wasn't even created when the Angels sent her to Hell, plus he rebelled! Things have changed in Heaven).