Rust

Prior to the Schism.
Rust, previously known as Woad, was a verdant paradise, some alleged to be a former Maiden World of the Eldar. After a weapons test went wrong, the world’s atmosphere was bombarded by so much radioactivity that most of the planets life withered and died. As an odd side effect, the lack of bacteria slowed down decomposition, making Rust’s once lush fields turn brown and sick. Despite this, some tribes still exist on Rust, and it is still a rare source of metals essential in the construction and repair of heavier battle armour such as Terminator armour.

During the Schism.
A work were everything is dying, but never dead. A maiden world of the old Eldar Empire known to them as Agetha, brought to ruin by a mysterious accident from a test firing Archeotech Weapon on Nolan. Before this though, there was the mystery of the vanished population there.

Here the Eldar returned, their intents not completely known as the Craftworld Eldar of Iybrasil followed the fates in search of the truth:  What happened here. An unwelcome foe waited for them, their appearance coincidence? The Archon known as Ozzy has long been suspected for the disappearance of the Maiden World now made Rust. The paths of the future always drew the inquisitive to his lap. Not a nice place to be.

From the offset, the Dark Eldar's advance was brutal and unforgiving, the survivors going to a fate worse then death. In one fell swoop they seized the Starport of Grenfelk and pushed the Craftworlders into a corner, where they wait to make their stand.