Consecrators

Consecrators
Battle Cry	Unknown, usually silent
Founding	Unauthorized. Although chapter is roughly two millenia old.
Successors of	Dark Angels
Chapter Master	Grand Master Nakir
Primarch	Lion El'Jonson
Homeworld	Fleet-Based, Fortess-Monastery: Reliquaria
Strength	Largely the same as the Dark Angels, but boosted by ancient relics, archaeotech, and other superior wargear
Specialty	Relics & Archaeotech. Arriving without warning and, upon defeating their foe, disappearing without a word.
Allegiance	Imperium of Man
Colours	Black with Red Stripes/ Old Dark Angels legion colors

A Consecrators Marine. Looks nothing like a pre-Heresy Dark Angel, Does he?

The Consecrators are a Chapter of Space Marines descended from the Dark Angels. Indeed, prior to the third century of the 40th millenium, there was absolutely no record of their existence. They just sorta appeared at chapter strength during the Second Kuppukin Schism, in which they annihilated the entire rebel high command structure in only six hours before vanishing again. They were once again absent from recorded history until three decades later, when the Chapter's 4th company was seen fighting alongside the Dark Angels at the Arrulas Intervention.

In the eighth century of the 41st millennium, the chapter's entire 3rd company went missing in the Jericho Reach after being ambushed by Orks and forced to abandon their strike cruiser, essentially going behind enemy lines in an ongoing warzone. Forces from the Angels of Absolution and Angels of Redemption were tasked to find them, while the Deathwatch made it their job to find and cleanse the ork-salvaged hulk. It is not yet known in the fluff whether the 3rd company or their vessel have been found. It is known however that they among the chapters that lost two companies at Darkmor, where the Unforgiven were lured into a trap Signus-style under the promise of Fallen Angels. This meant that the Consecrators were one of the few Unforgiven chapters that didn't bitch too much when they were ordered to take Primaris Marines, since a third of the chapter was missing and the Nu-Marines probably gave them a convenient excuse for not having to replenish the archeotech of their lost companies.

They appear to have inherited the most revered arms of the Dark Angels Legion, preserving them carefully through the ages. They bear a close resemblance to the First Legion before the Horus Heresy, maintaining the Legion's original black colour and exclusively wearing power armour that is beakie-pattern or older. This implies that the Chapter is either very old, or that the Dark Angels Inner Circle had them created specifically to retain the relics of the Legion... or the Dark Angels have so many relics and pieces of archeotech that they hand them out like candy to their Successors.

This absence of knowledge of their existence by the greater Imperium does not appear to be extended to the rest of the Unforgiven, who do seem to have at least some knowledge of their history, purpose, and current events. They were founded apparently in secret on the instigation of Supreme Grand Master Valafar on an undisclosed date, for the specific purpose of uncovering the mysteries of the Dark Angels' history. So we know this puts their inception at some point after the Second Founding and also most likely outside of any officially sanctioned founding as well.

Being one of the Unforgiven, the Consecrators share the Inner Circle, knowledge of the Fallen Angels, the Deathwing, the Ravenwing, etc. However, their Terminators are painted black with white helmets to signify the like to the Dark Angels First Company.

Deathwatch includes Consecrators as playable characters. To reflect the fact that they are equipped with such ancient and revered equipment, every character carries at least one master-crafted item as standard issue, though they don't have access to power armour newer than Mk.6 Corvus (although this is fine, as earlier marks of armour tend to have the best machine-spirits and traits), the game notes how this makes them suspiciously like a legion from the days of the Horus Heresy.

Their current Chapter Master Nakir holds the Inner Circle honorific of Master of Souls. He was an Interrogator-Chaplain prior to his appointment as Grand Master, having earned an impressive six black pearls for reasons. He also holds a Heavenfall Blade: the "Sword of Sanctity" which was recovered after being lost by the Disciples of Caliban but Azrael let him keep it.

If the Dark Angels ever get a Supplement, it should focus on these guys. They're different enough from the other Unforgiven to actually be distinct, and (perhaps more importantly) they would give players an excuse to field Horus Heresy-era weapons like Volkite ray-guns, rad-weapons, and Horus Heresy-era Terminator armour from Forge World. ...Or not, now that GeeDubs won't be releasing any non-Primaris models, don't hold your breath.

Symbol

The symbol of the Consecrators is a red abstract image, showing a ring consisting of probably-wings on the bottom and probably-a-halo above, with a flame in the center of the circle. Flame + Dark Angels = Firewing? Well, take a look at the Heresy-era marine on the right. This gentleman was an officer of the Firewing, and the symbol on his knee, while smudged and hard to make out, looks a lot like the Consecrator's symbol. Zoom in to see and you’ll notice it has detailed wings below a fire and above that a half halo. The whole is surrounded by laurels. In other words it looks almost exactly like the Consecrators’ symbol. So it seems plausible that they are not just Dark Angels descendants, but specifically made from Legio I's Firewing.

As of the Warhammer Community website's "Road to Thramas" update on the Hexagrammaton, it has been revealed that the Firewing specializes in "destroying enemy command structures", which seems to fit their modus operandi during the Second Kuppukin Schism.

The Living Relics short story by David Guymer sheds offers an interesting insight on the Consecrators, in that they are confirmed to be far younger than their wargear would have you believe. Apparently, they were indeed founded for the purpose of retrieving and preserving the history of the First Legion, specifically by snatching their archaeotech before others do (and also baiting Fallen with it).

Their Firewing iconography might be a deliberate attempt by the Unforgiven to make them pass for a Second-Founding chapter. An Ordo Astartes Inquisitor might have all sorts of theories about their Heresy-era wargear and isolationism, but it is unlikely they involve anything past M33, which plays right into the Unforgiven hands.