Captain Falx Carius was the Imperial commander of Fort Frostmoth. He was a Knight Protector of the Imperial Legion on Solstheim in 3E 427. During his time as Garrison Commander, Carius came into contact with the Nerevarine. Of no relevance to the choices made by the player in game, Carius found himself abducted by the Daedric Lord Hircine and forced against his will to partake in a series of trials during the events of the Bloodmoon Prophecy, along with others on Solstheim. He was forced to confront the Nerevarine inside the Mortrag Glacier, but it is unknown whether or not he survived this encounter.
His subsequent appearance inside Fort Frostmoth, and his increased rank (from Captain to General), imply that he was spared by the Nerevarine. He was presumably killed in the Eruption of the Red Mountain or its following ash storms. He was resurrected by a powerful necromancer and killed, ultimately, by the Dragonborn during the events of Miraak's Insurrection.
Carius most notably has no pupils in his eyes and a Heart Stone embedded in his chest. He wears a unique armor that has a chest design similar to General Tullius' Armor, but with a nearly identical appearance to the Penitus Oculatus Armor. His armor also has a brace which holds his heart stone in place, and he also wears unobtainable Imperial Bracers, boots, and an Imperial Helmet.
He is found during the quest March of the Dead inside Fort Frostmoth. He has been resurrected by a necromancer called Ildari Sarothril. At first, he tried to kill her and called her an "enemy" and a "spy." He can later be found behind a locked door.
He is extremely strong, capable of doing severe damage. He summons Ash Spawn to aid him in battle and uses the Champion's Cudgel, a unique warhammer that randomly inflicts fire, frost, or shock damage.
He wears unique equipment that looks identical to Imperial armor. Unobtainable through regular means, his armor can only be obtained via console commands. His equipment is:
- "Men, an invader has entered the fort! Prepare yourselves for an ambush!"
- The details of his reanimation from Ildari's Journal seem to be a reference to the classic Frankenstein's reanimation, such as the aimless assault and need for restraint.
- If his armor is removed using either console or mods, the heart stone is clearly visible on his chest.