Forged in fire, blessed by blood - the Legion of Machines has never lost to enemies of flesh but once the flames of wars were extinguished the Lord of Machines' Creator no longer saw a purpose in his continued existence and so he was sealed; his consciousness wiped from his body, left to rust on the throne he once ruled from.
His army dismantled and repurposed, leaving him alone in his tomb on a throne of steel - a ruler with no subjects, a shell with no soul, a relic of a past destined to be forgotten by the annals of history, the time where it was baptised in the blood of millions and created troops from the ruins of civilisations erased; after centuries all but the legends of his exploits have been lost to time.
But, it would truly be laughable if he hadn't once considered the possibility of betrayal; the return of the Lord to his steel throne was only a matter of time...