Malgrath's origin is the Citadel's most carefully guarded secret, kept even from Malgrath's own conscious memory. A century and more ago, he was a mortal cultist of a dying apocalyptic faith, a man who climbed the ranks of the Cult of the Hollow Crown through charisma and ruthlessness. When the Hollow King's whispers first reached the cult's founders, it was this man — whose name is now lost even to himself — who volunteered his body as a vessel for demonic ascension.
The ritual that made him Malgrath was performed with chains forged in the celestial realms, stolen relics that the Hollow King repurposed as instruments of binding. The chains were meant to be permanent, and in a sense they are: they cannot be removed, only studied. Malgrath does not remember his mortal name. He remembers only fragments — a face in a dream, a voice calling a name that is not 'Malgrath' — and he has trained himself to treat these fragments as weakness to be burned away.
His rise within the underworld was swift and brutal. When the Hollow King claimed dominion over the plane's ash-choked depths, Malgrath was granted the black iron Citadel as his seat and tasked with two great works: the maintenance of the legions, and the preparation of the rift-sigils that will one day tear open a passage between the planes. He built the Citadel's hierarchy himself, promoting mortal cultists to demonhood and binding imps, quasits, hell hounds, and erinyes into a disciplined military structure that other demon lords envy and resent.
His command over the legions is absolute within the Citadel's walls; through Infernal Command he speaks mind to mind with his servants and directs them with a bonus action's thought.
The ritual that defines him, however, is the transformation of Liora. The Hollow King instructed that the Dawnbringer — the brightest celestial to descend into the underworld in an age — be captured, bound, and implanted with the Infernal Seed, a parasitic demonic essence that will consume her celestial soul within a month and birth something new from her ashes. Malgrath believes this is a gift: that a successfully transformed Dawnbringer will be his masterpiece, his proof of worth, his key to a crown of his own.
He does not know — or refuses to know — that the Seed's true design is to create a vessel, and that the Hollow King has made identical promises to at least three other demon lords, Zharvek the Ash-Eaten among them.
Malgrath's relationship with the green flame is the strangest thread of his existence. The flame is his patron's medium: it burns in the ritual chamber, in the Citadel's braziers, in his own spells, and through it the Hollow King whispers instructions, praise, and threats. Lately the whispers have grown colder and more demanding, and Malgrath — in an act of quiet treachery that would cost him everything if discovered — has begun constructing a fire-well, a private channel through which he might hear the King's true plans and learn whether he is a servant or a sacrifice.
His resources are considerable: the Citadel itself, a network of cult spies reaching into the surface world, ritual magic of unusual sophistication, and the chained dungeons where escaped slaves' kin languish. His weaknesses are subtler: the lead box beneath his throne holding a shard of Liora's halo that he cannot destroy; the imp Vexx who stole a fragment of his binding rune and lives free in the Ashen Wastes; and the splinter of forgiveness lodged in his mind, which he fears almost as much as he fears the silence of the flame. He is a lord, a prisoner, and a performance all at once — and the campaign's true horror is that the Hollow King designed him to be exactly that.
