Stunus's right eye had been replaced with a bionic prosthesis. His nose, mouth, and jaw had all been removed and replaced with metal piping. After his lungs were injured, they too had been replaced with a mechanical construct. As a result, he absorbed nutrients externally through electrolytes and intravenous injections. Any Mechanicus sage with even slightly inferior technical skill would have been ashamed of the extent of Stunus's mechanical modifications.
Stunus's condition was not uncommon among the Iron Hands. In fact, becoming an Iron Hands veteran meant you could compete with the Chapter's Dreadnoughts to see who had less flesh left on their body.
The historical reasons behind the Iron Hands' obsession with mechanical modification were complicated, but the largest part of it was certainly deeply tied to Slaanesh and Fulgrim.
To the Iron Hands, reason and resolve were qualities a warrior had to possess, while weakness marked the beginning of destruction. They had witnessed far too many cases where weakness of will bred corruption and evil.
So what was strong? Naturally, steel and machinery. And what was weak? What could lead one into corruption? Naturally, flesh, Slaanesh, Fulgrim, and those damned Emperor's Children.
The sight of Fulgrim beheading a man before his children was simply too shocking, and the psychic shockwave caused by a Primarch's death had also bred a powerful daemon in the Warp known as the Sapphire King.
The Sapphire King's body had been forged from the frustration, fury, regret, unwillingness, and disappointment of unfulfilled ambitions that filled the entire battlefield of Isstvan III. After his birth, he became the inner demon every Iron Hand had to overcome. Every warrior who believed he had failed to protect his Primarch nourished the jewel-encrusted Sapphire King.
The Sapphire King was skilled at seizing upon the most vulnerable part of