The origin of this squad hails from during the time of Iyanden's wars with the corrupted Dark Angel Captain, Zhemon. This squad hailing from House Ulthanash was first called to action on the world of Ishasta and would battle alongside the wraith host raised to combat the fallen Space Marine. Whilst the ghost warriors led the attack on the fortress, Zhemon's Reckoning acted as a bodyguard detail for the council of seers who traveled with the war host. Though not exactly a combat role, the squad did see action during the closing stages aiding in the destruction of one of Zhemon's Maulerfiends. Sadly losing six of their members in the bloody attack.
Following the outcome of the battle the survivors of Zhemon's Reckoning now numbering only four, traveled with the Seer Council to meet with the Dark Angels. What happened at this meeting has never been discussed, but the four guardians returned to the craftworld changed. All four ultimately joined the aspect sects and met their ends in battle. But with everything on Iyanden these unsung heroes did not rest for long.
Now with the galaxy torn in two and a new God rising, this Guardian Defender unit is once again formed to fight the enemies of Iyanden. Still drawing from House Ulthanash citizens, who take it upon themselves to don the war masks and fight in honor of the original members. Of the original members their story didn't end in death, it is whispered that they now have rejoined the living as Ghost Warriors and once again travel together as a unit with a strong thirst to fight traitor and loyalist Space Marines. Some even bearing the mark of the Ynnari on their bodies.