Primus, The One and the Prime, Cube.
Discovered at the heart of a cult in the Caves of Chaos, this seemingly metallic cube was used by Abel Seph to create undead abominations before his destruction at the hands of a group of adventurers.
Released from the cult’s power, Primus was given the appellation “Cube.”
It is composed of some unknown golden metal that seems impervious to harm. Roughly a foot in each dimension, Cube can transform its shape to that of nearly any metallic object. It speak telepathically, and seems to have an encyclopedic knowledge of Eberron, current events and the Last War, though it knows nothing since the Day of Mourning.
It cannot recall where it came from or how it ended up in the caves, and the extent of it abilities are unknown.