M'Pandex - Horus Heresy: M'Pandex's involvement in the unfurling Heresy began in 006.M31, at the height of the spreading alarm throughout the Cyclops Cluster. Both Mezoa and M'Pandex, the two greatest independent powers within the region, each received the Emissary of Mars, a magos known as Regulus, or at least an entity bearing that name as there are extant contradictions in the record regarding the location of this individual at various times.This senior tech-priest of the Mechanicum had for many Terran years served alongside the Warmaster Horus, long before the betrayal at Istvaan, and now remained his, body and soul, being part of Horus' inner circle and bound in allegiance to the Traitor's cause.Regulus came bearing dual patents of authority, the first from his Warmaster and the second from the hand of Kelbor-Hal, none other than the fabricator-general of Mars, and by right the voice of the Omnissiah and Supreme Pontifex of the Mechanicum.Kelbor-Hal had also thrown his lot in with the Traitor Horus, sparking a civil war on Mars itself, a fact not yet known by those in the Cyclops Cluster. Regulus made an offer and a demand; the demand was for fealty, that the Magi of M'Pandex serve the Warmaster as their own Fabricator-General bid them to do.That they obey him and offer up their arts and the fruits of their forges for him and his armies, and open their ports to his warships, while denying these things to both the forces of distant Terra and the local Imperial Commanders, already demonstrably squabbling amongst themselves in fear and disunity.To honey the threat of force, Regulus offered the Warmaster's protection for their Forge World and, just as he did to sway Kelbor-Hal to his cause, he offered gifts: STC technologies harvested from the later Great Crusade era and kept solely by Horus and those he trusted, and the freedom to pursue those technologies and arcana the Emperor had so cruelly and ignorantly denied them as forbidden knowledge since the Treaty of Mars.On M'Pandex, Regulus was greeted with great reverence and courtesy, and personally led to direct audience with the High Ourteka of M'Pandex to plead his case. What passed between them at this private conference is unknown, but from then onward and without recourse to consorting with the synod of M'Pandex magi for confirmation, the Forge World was pledged to the Warmaster.There was in some quarters brief but violent resistance to this new order, but the world was long-used to internecine conflict in its ranks, and the High Ourteka was merciless in wielding the handful of Martian Skitarii and the small detachment of Legio Mortis Titans based there to aid in his world's protection, now his private enforcers, to ensure compliance.This new allegiance, while firm, was not widely broadcast and was unknown to outsiders. M'Pandex was quickly girded for war, its production capacity ramped ever higher and now destined for Horus' armies, while whatever Loyalist or merchant voidships passed into its space were seized and impounded, their crews and complement forcibly converted into adsecularis slaves for a growing Taghmata of the Forge World's own.M'Pandex's military and especially its naval might was quickly put to good use, reinforcing the blockade of its long-time rival Mezoa and seizing its vassal worlds for precious resources which quickly fuelled M'Pandex's war effort.