- Defence of Tophet VI (Unknown Date.M41) - When the Imperial Forge World of Tophet VI is attacked by an invading force comprised of the hated Iron Warriors Traitor Legion, the Imperium response in force. They send a joint task force consisting of the unforgiving Subjugators Space Marine Chapter alongside the god-engines of Legio Debellator. The battle between the two opposing forces are terrible, as the Iron Warriors are masters at siege-craft, but their forces are further augmented by the surprising appearance of a fallen Warlord-class Titan that spearheads their attacks. Surprisingly, this massive Titan bears the heraldry of the Legio Debellator. To their shame, the loyalist god-engines identify the Warlord Titan as one of their own - the fallen Ecce Bellum - which had been thought lost by the Legio during a previous campaign, when it was sent as part of an Adeptus Mechanicus strike force from the forge world of Agripinaa, into the Eye of Terror. Armed with a pair of Volcano Cannons, the deadly power this formidable god-engine carried, could easily carry the day for its dark masters if the Legio Debellator couldn't counter this dire threat. As the Forces of Chaos assaulted the forge world's primary hive city they managed to breach its walls, however, Ecce Bellum was caught in an ambush by a Legio Debellator Warhound Scout Titan maniple. Despite landing several well-placed shots, the damage was only minimal, and the Warlord Titan quickly gained the upper hand as it crippled both the Argentum Sororis and Ruber Captrix with a deadly psychic attack. However, thanks to the quick actions of Princeps Roan Asander, of the Warhound Titan Ruber Captrix, he was able to contact the fallen Warlord Titan's Princeps Demaratus, reminding him of his duty to the Emperor. Getting through to him for a brief moment, the corrupted Princeps was able prevent the Ecce Bellum from firing its weapons long enough to allow the Ruber Captrix the opportunity fire its Plasma Blastgun directly through the Warlord Titan's faceplate, destroying the larger Titan's command crew. In the wake of the destruction of the Ecce Bellum, the Forces of Chaos were driven back by the Imperial forces and Tophet VI was secured.
- Ecce Bellum (Warlord-class Titan) - Captured and corrupted by the forces of Chaos and destroyed during the fighting on Tophet VI.
- Argentum Soraris (Warhound-class Titan)
- Domina Mortis (Warhound-class Titan)
- Regina Verum (Warhound-class Titan)
- Ruber Captrix (Warhound-class Titan)
- Princeps Cynna - Princeps of Domina Mortis.
- Princeps Roan Asander - Princeps of Ruber Captrix.
- Princeps Demaratus - Fallen princeps of the Ecce Bellum; deceased.
- Moderatus Berowne - Moderatus of the Ruper Captrix.
- Moderatus Vyola - Moderatus of the Ruper Captrix.
- Komnena - Tech-priestess of the Ruper Captrix.
The Legio Debellator primarily paint their Titans dark tourmaline red, which appears almost black.
The badge of the Legio Debellator is a pair of stylised gold coloured lionesses heads, in profile, facing away from one another.
This pair of symbols sits on opposite sides of the central symbol -- the stylised 'T' for the Collegia Titanica.
Beneath these central symbols is a gold coloured laurel.
- Servants of the Machine-God (Anthology), "Hunting Ground," by Ian St. Martin
- Hunting Ground (Short Story) by Ian St. Martin