Orga, The Beast.

She is the byproduct of an experiment held by Archmagos Dominus Belisarius Cawl of the Adeptus Mechanicus.

In his attempt to create the Primaris Space Marines, he studied the physiology of multiple different xenos species, notably Orks. He attempted to create a new strand of transhuman super warriors by creating a hybrid between Orks and humans.

Hence, Orga was born.

However, Cawl was not satisfied with his work and deemed her a disappointing failure.

Whilst Orga was exceptionally strong and powerful, she was not what Cawl wanted her to be, and so, he attempted to get rid of her.

In an attempt to see where he had gone wrong, Cawl gifted the young Orga to the Adeptas Custodes, thinking that the intense training would kill her and provide valuable data on how to improve. Orga, however, not only survived but thrived.

Her talents proved so monstrous that the venerable Trajann Valoris himself offered to train her.

Unlike most Custodes, the intense training did not wash away Orga's personality and emotions. Orga is kind, soft-spoken, and slightly naive.

She has a special relationship with Lord Roboute Guilliman and sees him as an uncle.

In battle, she dons a heavily modified Contemptor Galatus Dreadnought power armour that uses two massive power claws. This Dreadnought Power Armour is specially made so it can be taken on and off, similar to a Warsuit.