Agni

"Named after a layer of Limbo, Agni is a symbol to devoted chaos worshipers, beings of evil primordial nature who have lost their ways and taken chaos as a way of living. It is no wonder that fey have taken a liking to the chaotic dwellings of our universe, many of them share similar traits to the first Nameless God. Physicality aside, the closest any have been to usurping the throne of "God of Chaos" was never a god at all, merely a spawned fey from the Spawning Stone known as "Worldbringer", for even life was too little for Them". - Passage from "Solarian Incendium", from a forgotten world.

Harboring the three souls of despicable hags devoted to an order of chaos, this weapon reflects their very inner chaotic core. One of the highest ranks of honor a hag could have is to be imbued into a spell or weapon of other kind after their passing, to be used by a rightful powerful master. However, any of sane mind would feel themselves fall into madness and hysteria upon touching the sickening metal of this weapon, forged from iron and stone of the Spawning Stone itself. You gain a +3 bonus to attack and damage rolls you make with this magic weapon. At the start of combat if you do not have any hit dice remaining you regain one hit die for each charge remaining (minimum of 1.)

Weeping Bellows: The first time you damage a creature with this weapon, that creature must succeed on a WIS saving throw (12) or will be marked as blood begins pouring from their eyes- you may use a hit die to forego the saving throw. For until you attack the creature again with this weapon, or attack a different creature. A creature may only be marked this way once per long rest. The marked creature becomes frightened of you. Upon damaging this creature a second time with this weapon, they turn to Raging Mirth
Raging Mirth: The second time you damage the marked creature, their tears will begin to scorch as their blood literally begins to boil. The target must make a DEX saving throw (13) or become restrained and take 3d6 fire damage, or half as much on a successful save. 
Bickering Silence: Regardless on if a creature is marked or not, any time you damage a creature for a third time with this weapon, their blood will form into intense sharp spikes until the end of their next turn, any attack that creature makes will be at disadvantage and they will take 1d6+2 piercing damage. You will also gain a hit die

Flagellate. As a bonus action you can spend a hit die to strike yourself with this weapon, imbuing the weapon with fresh pain. Until the end of your turn attacks made with this weapon deal an additional die of necrotic damage of the same type as the hit die spent/damage taken.

Bloody Proliferation. As an action you can spend 4 hit dice to flourish this weapon around you and create a zone of sanguine pain as thorns of blood lash across the battlefield. You make a melee attack with this weapon against any number of creatures within 20 feet of you (even if the target is outside of the normal range of this weapon). You must roll a separate attack roll for each target.

Sickening Exchange: If you are unable to use a hit dice, you may instead take 1d10+4 necrotic damage. 

Joining the Chaos: When first becoming attuned to this weapon, the chaotic surge will flow with the wielder's, by rolling a 1d3, the wielder will take on a semblance of one of the hag's sentience. Adding one of the hag's ideals to the wielder's.

1 2 3

Famine: I hunger for freshly killed flesh of any kind, any kill I make must rightfully be eaten. Conquest: I can only kill with the rage within this weapon, any other weapon sickens me. Death: I have taken a liking to pain and my life feels numb without it. I will frequently seek out ways to harm myself. And hurt myself with this weapon as much as possible.

Proficiency with a Flail allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Magic, Damage: Fire, Damage, Combat, Sap