Relictors

Relictors (Fire Claws)
Battle Cry	Strength of Will, Courage of Will
Founding	Unknown Founding (M36)
Successors of	Unknown
Chapter Master	Artekus Bardane
Primarch	Lion El'Jonson or Roboute Guilliman (or both)
Homeworld	None (formerly Neutra)
Strength	Near-extinct (old Lore) Unknown (5th Edition onward)
Allegiance	Imperium of Man (well, kinda)
Colours	Grey with black shoulder pads

The Relictors (formerly called the Fire Claws) are a renegade Space Marine Chapter in Warhammer 40k. Most of their fluff was written in the lead-up to the 13th Black Crusade summer campaign... and only a few mentions since then.

History (Pre-5th Edition, Eye of Terror Era)

Essentially, they're like the radical Inquisitors (Xanthites, in particular) that believe they can fight Chaos with Chaos. Indeed, their current name (Relictors) comes from their unhealthy obsession with Chaos-related artefacts and weapons. Of course, why a normal bolter didn't suffice is unclear. Possibly because using a bolter that burns the target’s soul or banishes daemons in one shot is vastly preferable even if it uses bits of your own soul as ammunition.

They were put on such a path by a rogue Inquisitor who introduced their Chief Librarian (totally not Azariah Kyras) to his views; culminating in a single desperate event where the Librarian used a daemon weapon to kill a Chaos Warlord,

Taking the fact that he could use a daemon weapon without immediately melting into the gribly beast that the orthodox Inquisitors tell you will happen when you touch such things, the Librarian took it as a sign of Big Emp's permission to start using Chaos gear, and introduced his new way of thinking to the rest of the Chapter.

Over time, the two forces hoarded an impressive amount of Chaotic bling. Their primary goal was to obtain the "Axe of Angron" which had been broken into several pieces and scattered across the galaxy. They believed it was some kind of super weapon that would help save the Imperium from its impending doom. Though if they knew anything about Angron, they would have realised that he broke his weapons into multiple pieces through overuse all the time and there are probably bits of them on every planet he ever visited.

However, their quest for Chaos loot was cut short when their allied Xanthite Inquisitor got the chop. The Chapter at that point was allowed to go on its way if it agreed to give up their homeworld and go on a hundred year penance crusade, as well as swearing never to listen to creepy strangers bearing shiny toys ever again.

So they became a fleet based Chapter, but totally ignored everything else that was mentioned.

War for Armageddon

The entire chapter heeds the call to fight during the Third War for Armageddon.

Having known about the planet's history, they knew that it was the site of a major Chaos incursion during the first war. (Something that was such a big secret for the inquisition to go to war with the Space Wolves over, but whatever)

They busied themselves in the deep jungles of Armageddon, telling the Imperial Guard and Lord Dante that they were purging the Feral ork tribes. Even though every military commander and their dog was telling the Relictors there were more important things to be doing.

The Relictors were looking for (and found) one more piece of Angron's axe, and when they got it they departed the battlefield, aiming for they Eye of Terror, with the foreknowledge that shit was about to hit the fan.

However, their refusal to adhere to commands, and the fact they ditched the war for Armageddon, particularly when their intervention could have saved some key hive cities, earned them no friends amongst Imperial Command, with both the Imperial Guard and Dante separately complaining to the High Lords of Terra to do something about them.

Excommunication

The final straw was during the 13th Black Crusade where they attacked an Inquisitorial facility to obtain yet another daemon-artefact.

The Inquisition (and the greater Imperium) was hardly impressed by what they saw as dangerous heresy and team killing (on the greatest team-killers in the galaxy). At that point, any notion of restraint left the Inquisitors' heads and they sent the Grey Knights against the Chapter's orbital fortress monastery. While the Chapter was badly mauled, it is rumoured a few hundred Battle-Brothers survived and fled to the Eye of Terror... leaving the door open for you to collect your very own horde of them!

One lone Relictors Techmarine ends up in the retinue of Inquisitor Bronislaw Czevak, though he's fairly disconnected from his brethren, and since Czevak is also considered a dangerous renegade of his own by this point the association with the Inquisitor isn't helping clear up the name of the Chapter.

Still, they appear every so often in the background; for instance, Be'lakor leads a group of them into an ambush in his 6E Dataslate for 40k. A presumably radical Inquisitor also mentions them as allies in Imperial Armour Volume 13, indicating they still have some friends in the Inquisition too despite being declared renegades. Probably because, much to everyone's shock, they are using Chaos either without being corrupted or at least even if they are corrupted they're still somehow loyal to the Imperium. Lore does have at least one full-blown Chaos Marine turning back to the Emperor and attempting to assassinate his Chaos Lord for redemption (fails and gets crammed in a dreadnought) so we know even Chaos Marines can become loyalists again. Perhaps the Relictors are so obssessed with their belief of being loyal yet using Chaos that they're loyalist Chaos Marines.

Come to think of it, they're basically Blood Magpies with extra heresy.

But Wait! Let's roll back the clock! 5th Edition Codex and beyond

Amusingly, come the 5th Edition Space Marines codex, the status of the Relictors have once again been rendered ambiguous, ignoring the results of the Eye of Terror campaign entirely. Seeing as the timeline at that point hadn't advanced prior to the 13th Black Crusade, nothing has been mentioned on the Chapter's bout of heresy, or going renegade and packing their bags for the Eye of Terror.

Which could be a good or bad thing, depending on where one stood on the Loyalist/Renegade side of the collectors equation. On one hand, this is a good thing for a Loyalist collector, as it leaves things open for the Chapter to collect a lot of new stuff (flyers like the Stormraven, Centurion Squad war suits, etc.); on the other hand, the Chapter lost a lot of the flavor going Renegade gave it, as otherwise they're just another Codex Chapter among twenty others in the Astartes Praeses. A shady Chapter for sure, but still Codex adherent.

Gene-Seed

In one moment of derp, it's stated that their Gene-Seed stock is composed from both the Dark Angels and the Ultramarines making them a hybrid Chapter.

What is not so clear is what this actually means to them genetically, if whether their gene-seed is actually a crossbreed of the two, which makes them almost entirely unique in the 40k universe for being a "stable" attempt at dicking with the Astartes gene-pool (see the Cursed Founding as to why this is considered a bad idea, and see the Horus Heresy series for why manufacturing "new" gene-seed is all but impossible).

It is equally possible that the Chapter is simply made up of brothers from two different bloodlines, which doesn't necessitate mixing gene-seed. Which makes one wonder why the legions weren't all made that way. Each one (and the later Chapters) were/are quite selfish about most of their recruiting worlds. Yet, there will be plenty of members of the populace suitable for a different legion than the one recruiting there. The Chapters have not be mentioned to find such people and send them to the right legion for recruitment and probably grow old and die never knowing they could've been Space Marines. Mixed heritage in Legions and Chapters would have efficiently fixed this while allowing for the instinctive specialties designed into their genetics to complement each other within the Legion/Chapter to kick even more ass.

However, if they are descended from the Dark Angels, it goes a long way to explaining their predilection for quitting battlefields without warning and being anything but team-players. If they are Roboute's sons then that explains their predilection for falling to chaos.

That they are descended from the Dark Angels is now seeming more likely, as Chaplain Asmodai made a deal with a Relictors Captain to capture a member of the Black Legion in exchange for an artefact of unknown provenance, which was "rightfully" Asmodai's to give, and was "rightfully" the Relictor Captain's to protect, and was kept in a locked box until the mission was completed. After capturing the traitor, Asmodai lived up to his end of the bargain and told the Relictor that the box was keyed to specific genetic markers and would open for the captain just as it would for the Dark Angel. Not quite an explicit confirmation of the Relictor's origins, but certainly an implicit one.