The Angels of Fenris are a Space Wolves descendant chapter. The chapter was built with 3 tasks to accomplish:

1) Perform secret operations within the Eye of Terror
2) Locate Leman Russ
3) Kill Magnus The Red and rid the universe of his accursed Geneseed and the Thousand Sons.

How they were to accomplish this has also been kept under lock and key for quite some time. Officially, it was due to them being made up from the Sons of Russ that showed a particular resistance to the Warp, but this is only half the reason. The other half is where their name comes from. Their champion, a Living Saint, Saint Remas.

They wear the Russ Grey of their founding chapter, but have a gold trim, rather than the Fenrisian Grey, and have Red elbow and knee armour. Their symbol is of a striding wolf with a pair of wings on its back. Their Chapter Master is a young, but talented Rune Priest Lord by the name of Kurn Wolftalon.

Burning Sword of Morkai (A Sword designed by Angels of Fenris' Master of the Forge, Lemanicus Bridge, and forged by the finest Techmarines that The Fang has to offer, this is a large burning sword, which, thanks to her physiology, she can wield with but 1 hand)
His Holy Words (A wrist mounted twin-link Melta gun, used to turn her opponents into molten slag. It is said that each shot cuts through a heretic like the unquestionable words of the Emperor.)
Gauntlet of the Allfather (A unique Power Fist weapon, based off of the design of The Emperor's Gauntlet, has "His Holy Words" mounted onto the wrist of it. It's smaller to make it more weildly, but the technologies within it grant it just as much destructive force as it's larger counterparts.)
Wolf Amulet

Armour of Saint Remas (A Special Runic Armour designed for maximum protection and maneuverability. The armour itself is based off of the MK IV "Imperial Maximus" Power Armour and was crafted by the Techpriests of Mars.)

Strength: Being a Living Saint, she has vast Strength, enough to lift a large her sword and swing it with the precision that most of her ilk do.

Wings: Thanks to her incredibly powerful Wings, combined with her armours power, she is able to fly as though she had a Jump Pack on.

Acts of Faith: Like her Sisters, she can perform Acts of Faith, psyker-like powers that grant her extra power, but can only have one active at a time.

Presence of Morkai (Grants her a Fear Aura, causing those that look upon her to be filled with dread.)
Act of Thunder (Grants her the Living Lightning ranged attack. A lightning bolt that shoots from her hand that homes in on its target.)
Beacon of Faith (She and her Allies around her are filled with inspiration, slowing their heartrate and allowing them to think calmly in the heat of combat.)
Avatar of the World Wolf (Fills her with the power of the World Wolf. Grants her a dramatic boost in her strength, but puts her into a feral state where she is filled with the inquenchable lust for the blood of heretics, xeno's and mutants. She foresakes the use of her ranged weapon in this state and favors her Power Fist to her sword.)

Born on Fenris, she was excommunicated from her tribe when her Wings grew at the age of 5, believing her to be a witch. They believed that she would die in the frozen wastes, but she quickly grew to have a natural affinity with the Thunderwolves of the planet. Using this power, she traveled to the tallest mountain on the planet (Where the locals believe the great hall of the Sky Warriors exists, but no mortal has ever gone and returned) and entered the great fortress known as The Fang. She was about to be executed as a Mutant, when Ulric stepped in, stating that she was a daughter of the Ecclesiarchy, that mutants do not grow anything beutiful, but instead wings that are twisted and horrific. Her pure white wings could only mean that she had been blessed by the Allfather, just as Sanguinius had been. This was just as the Time of Shame had ended and the Space Wolves and Inquisition only saw eye to eye because it would be mutually assured destruction to do otherwise. Without the Space Wolves to guard the Eye of Terror, Chaos would pour through, but the Space Wolves were heavily outnumbered and outgunned by the Inquisition.

Remas was a secret of the Space Wolves for quite some time, until finally, a Blackship picked up the psychic essence of a Living Saint and the jig was up. This event almost led to a second war between Inquisition and Space Wolves, but, thanks to her loyalty to Russ and the intervention of Bjorn the Fellhanded, the oldest and wisest space marine alive, they came to an agreement that she would become the head of a new Chapter of Space Wolves and would be the one to slay Magnus. She has been personally trained by the best that the Space Wolves and Inquisition has to offer. She is of Fenris, meaning that she is a hearty warrior, like her brothers, the Space Wolves, not a cold, callous one-woman-army like the other Living Saints.