The Plague King Chagatai

Lion might not have known what an Ouroboros was, nor what the Heart of Pestilence was, but he knew the last thing.

The Tuchulcha Engine.

After discovering the Tuchulcha Engine in the Perditus system, he had even fought a fierce battle with the Death Guard led by Calas Typhon before successfully taking possession of it.

It was precisely because Tuchulcha could perform Warp transit with such efficiency and precision that the Dark Angels had more easily defeated the Night Lords and Konrad Curze, then broken through the Ruinstorm's interference to reach Guilliman's Macragge.

Thinking back carefully, Lion realized that his connection to the Tuchulcha Engine ran astonishingly deep.

It could be said that without this xenos creation of unknown origin, the state of the galaxy today would have been even more unfathomable.

Without Tuchulcha, he could not have broken through the Ruinstorm and followed Pharos's light to rendezvous with the Five Hundred Worlds.

And without that rendezvous, would he have been able to reach Terra now and command the Imperial forces against Horus here?

Faced with Imperial defenders lacking reinforcements, Horus would have attacked Terra more easily and brutally.

Lion did not dare imagine how terrifying it would have been had he never returned to Terra.

He had always considered himself the most loyal Primarch, but if he had missed the entire Great Rebellion and led the strongest Dark Angels Legion around aimlessly, was that loyalty or disloyalty?

The Lion wiped these distracting thoughts from his mind. Many things could not bear too much thought; overthinking bred heresy, and heresy led to betrayal.

"I had originally believed Tuchulcha was the creation of some extinct xenos civilization," Lion said.

"There are many xenos creations of unknown provenance like it in the Dark Angels Legion's sealed vaults, though a large portion have