I was a playtester on Courtney Campbell's Perdition, and am currently a player in his campaign, which is why I haven't reviewed it here, but I do like it. The corebook mainly has devil lords as patrons for PCs to take on. In Courtney's own game, we have at least one of the Old Gods written up as a patron, and my previous character (who just died last session) was one of his initiates (possibly the only one). I thought I'd write up some demonic ones just to balance things out.
For those unfamiliar with the campaign setting, devils in Perdition are expressions of law. Bad law, certainly, but still ultimately the law. Demons are the forces of raw chaos who want to undo the existence of every constant in it, from society to gravity and everything in between. They want to do so as a way of undoing the divine act of creation. I thought it would be more interesting if they all disagreed about what undoing creation would look like.
Acedius Vex, the Welter of Meaning
Demon Lord of fungibility, distraction, sensory overload, inversion, ambivalence and mathematics
Acedius Vex is the scar over the wound carved through primordial matter when the first thing was separated from the totality of everything. It is the interdependence and fungibility of all impermanent and imperfect things, real and unreal, possible and actual, trivial and great with, one another. It is the chaos of a thousand things happening at once, each so quickly that one cannot distinguish them, the impersonal viewpoint of the whole looking down on the mereness of the particular, the riotous meaninglessness of sensory overload. Focus, concentration, determination, an insistence on the value of the true and good over the false and wicked, the individual who seeks to distinguish themselves, these are its enemies. It is the pause to admire the sky in the midst of a battle, the admixture of pungent scents, the dance to avoid trampling ants as one flees for one's life, the anxious pause as one considers what to say, the daydream overlapping with one's waking life.
Its goal is a world in which the difference between one thing and another does not hold, where each becomes other, and another, and itself, all at once, relentlessly. Its vision is one where the weak become the mighty and the mighty become weak, where cunning mathematics reveals the hidden equivalences of all things, where flesh devours its own before being devoured in turn. It craves transmutation, profusion and ambivalence in all things as reflections of their fundamental emptiness. It despises the cold, calculating focus of the undead, the obsessive devotions of the addict and the lover, the dedicated rapture of the artist.
Acedius Vex appears as profuse, rambling, enciphered speech, the linguistic equivalent of an irrational number, an endless never-repeating flow of words that contains all patterns and all possibilities within it while yet exceeding them in its development. Once one begins speaking Acedius Vex, one can never stop. In time, those who hear it spoken often enough begin to find themselves muttering some part of it in turn. The skulls of its speakers continue to chatter speechlessly even after death, until they are worn down to dust faintly shimmering in secret ciphers.
Its herald is a crowd of madmen shouting and hooting nonsense who crew a black boat that sails through the air on the multicoloured rays of dawn and dusk. Its followers are mutant proselytes in animal masks who rave and pray in vivid and unforgettable ceremonies.
Never insist on the importance of one thing over another in conversation
Never refuse to eat an intelligent being if offered
Never avoid an act because of the long-term consequences
Never become addicted to anything
Never fall in love
Reveal that one thing has actually been another all along (+1)
Cause sensory overload in another intelligent being (+1)
Pause in an urgent situation to speculate irrelevantly (+1)
Eat a being of the same species as you (+1)
Destroy a powerful undead being (+1)
Being blinded, deafened, or muted (-1)
Sleeping through the dawn or dusk (-1)
Accomplishing a long-term goal (-2)
2: You gain +4 on saves vs. charms, compulsions, and obeying orders.
3: You gain Darkvision, which manifests as the ability to narrate aloud what is in front of you in the darkness rather than actual sight.
4: Once per day you can cause a mirage to form as if you had cast Rainbow Pattern.
5: You gain a +4 to hit with any social attack that is ludicrous.
6: All enemies within 2" of you must save or become Distracted until they are no longer in range.
7: You may roll on the chaos mutation table whenever you wish, as many times as you wish. The changes are permanent and cumulative.
8: Three times per day, you may exchange the current hitpoint totals (both mental and physical) of any two living creatures you can point at as a [Action]. The creatures must each have an equal or lesser number of hit dice than you do, and may save if they are unwilling.
9: Once per day, you may change the state of any 10x10x10 cube of unliving matter from one state into another - water into ice, bricks into gas, dirt into plasma, salt water into crystals. You are limited only by your knowledge of the states of matter. This change lasts for 1d6 turns.
10: You can make up the names of things at will. These names function as if they were the original ones for the purposes of rituals you cast.
11: You may treat any illusion as if it were real and gain the benefits of doing so. Conversely, you may no longer disbelieve illusions.
12: You gain the blessings of Acedius Vex. You no longer experience critical hits from physical damage, as no part of you matters more than any other. You do not accumulate Stress or suffer damage from it. Anyone you render helpless in a grapple must save or become you, transforming over the course of one round into a perfect copy of you with the same stats (including current hitpoints, spell dice available, etc.). The copy lives for 13 hours then dies.
Edit: I've updated Acedius Vex's powers in line with Josh's advice in the comments. This primarily affects bond levels 6, 8, 9, 10, 11 and 12.