Samael

Samael () (also Sammael and Şamil) is an archangel in Talmudic and post-Talmudic beliefs and stories, as well as Christian tradition and demonology. There are also other religions that believe in stories of Samael. It is said that he was the guardian angel of Esau and a patron of the sinful empire of Rome. 
Samael is often accorded with Satan because he often has grim and destructive duties. He is often considered a fallen angel, like Satan and the chief of the evil spirits. One of Samael's roles in Jewish beliefs is that of the Angel of Death. In this belief, he is a fallen angel but remains one of the Lord's servants. As a good angel, Samael supposedly lives in the seventh heaven, although he is said to be the chief angel of the fifth heaven. 
Powers.
The website Catholic.org says Samael is a "Power", which means he is the chief of many warrior angels.
Powers are warrior angels against evil, who defend the world and people. They fight against evil spirits who attempt to bring chaos through human beings. The chief is said to be either Samael or Camael, both angels of darkness.
In Judaism and Christianity.
In Jewish beliefs, Sammael is said to be the Angel of Death, the ruler of the Fifth Heaven, and one of the seven regents of the world served by two million angels; he resides in the Seventh Heaven. "Yalkut I, 110" of the Talmud says Samael is Esau's guardian angel. In "Sotah 10b", Samael is Esau's guardian angel.
In the "Sayings of Rabbi Eliezer", he is said to be the one who tempted Eve, then seduced and impregnated her with Cain. Some sources identify Gadreel as the angel that seduced Eve; although, other Hebrew scholars say that it was Samael who tempted Eve as the Serpent. 
Samael is also sometimes said to be the angel who wrestled with Jacob, and also the angel who held back the arm of Abraham as he was about to sacrifice his son.
According to "The Ascension of Moses" (Chapter IV - Aggadah - The Legend of The Jews - By Louis Ginzberg) Samael is also mentioned as being in 7th Heaven:
"In the last heaven Moses saw two angels, each five hundred parasangs in height, forged out of chains of black fire and red fire, the angels Af, "Anger," and Hemah, "Wrath," whom God created at the beginning of the world, to execute His will. Moses was disquieted when he looked upon them, but Metatron embraced him, and said, "Moses, Moses, thou favorite of God, fear not, and be not terrified," and Moses became calm. There was another angel in the seventh heaven, different in appearance from all the others, and of frightful mien. His height was so great, it would have taken five hundred years to cover a distance equal to it, and from the crown of his head to the soles of his feet he was studded with glaring eyes, at the sight of which the beholder fell prostrate in awe. "This one," said Metatron, addressing Moses, "is Samael, who takes the soul away from man." "Whither goes he now?" asked Moses, and Metatron replied, "To fetch the soul of Job the pious." Thereupon Moses prayed to God in these words, "O may it be Thy will, my God and the God of my fathers, not to let me fall into the hands of this angel."
In "The Holy Kabbalah" (Arthur Edward Waite, 255), Samael is described as the "severity of God", and is listed as fifth of the archangels of the world of Briah. Samael is said to have married Lilith after she left Adam. According to Zoharistic cabala, Samael was also mated with Eisheth Zenunim, Na'amah, and Agrat Bat Mahlat - all angels of prostitution.
Samael is sometimes confused in some books with Camael, an archangel of God, whose name means "He who sees God".
Popular culture.
Samael is shown as a character in the Megami Tensei video game series. The archangel is shown in the games as a blood-red serpent. He is a member of the Vile Clan and is a persona of the Death Arcana. 
In the Silent Hill video games, Samael is the name of one of the town's gods. He is shown as an anthropomorphic goat.
In the film Hellboy, one of the main characters is a giant hell-hound called Sammael, who Hellboy nicknames "Sammy".
In Lucifer, the TV and comic series, Samael is Lucifer Morningstar's original name before he left Heaven. 
Samael plays an important role in the central plot of the first Darksiders title.
In the web cartoon Purgatony, Samael judges the souls of the dead while working in an office in Purgatory.
In the manga and anime Blue Exorcist, Samael is the true name of the demon Mephistopheles, and he is a son of Satan as well as a brother of Lucifer. As in biblical legend, he displays both good and evil aspects, but is the demon of Time rather than of Death.