The Forgotten One is an ancient demon lord who was patron to the vermin. Weasels, rats, mice, all other small creatures that were subjected to scorn and ridicule - often times culled in favour of other, more powerful beings - pledged themselves to this entity in hopes of finding salvation. Those who worshipped this creature were filled with such zealous devotion that they blindly obeyed and carried out its orders; spreading plagues and disease in order to further the means - complete annihilation. So cruel and violent was this creature that it consumed the souls of those who wanted allegiance in effort to increase its power.

To be bound to the Forgotten One is to understand that what little time you have left as a mortal will soon be replaced with unimaginable suffering and torment at the hands of your sadistic master for the remainder of your existence. As you roam the material plane and enact the Forgotten One's will, your essence is slowly consumed by a hunger that knows no end.

The creature has one goal: to feed - and it will continue in perpetuity until either its hunger is filled, or it destroys itself by having no followers to carry on its mantle of destruction.

Breath of the Abyss

Starting at 1st level, you can exhale a 15-foot long cone of blistering embers as an action. Creatures within the cone must make a Constitution saving throw against your warlock spell save DC. Creatures that fail take fire damage equal to your warlock level + your Charisma modifier, and are blinded for one minute. They can repeat their saving throw at the end of each of their turns, ending the effect on a success.

Once you activate this feature, you cannot do so again until you finish a short rest. Additionally, you can breathe and see normally in smoke or ash-filled air

The Master Feeds

Beginning at 6th level, the Forgotten One empowers you with a fragment of its terrible hunger. Whenever you move during combat, you can choose to leave behind a trail of ash that hangs gently in the air, lightly obscuring the area until the start of your next turn. Whenever a hostile creature enters this trail, you can use a reaction to summon a set of flaming fangs to bite them. Make a melee spell attack roll against the target. If you hit, the target takes 1d10 fire damage

Relentless Persuit

At 10th level, your patron grants you a portion of its primal stamina. You gain resistance to fire damage. Whenever you finish a short rest, you can choose to reduce your level of exhaustion by one. You can do this twice, and you recover these uses when you finish a long rest

Abyssal Retribution

At 14th level, you unlock the power to incarnate in the form of your patron. As an action, you assume the form of a Medium or Large vermin creature wrapped in flame. Your statistics are unchanged, and your equipment merges into your new form but still functions as normal. For 1 minute, or until you exit this form as a bonus action, you gain the following benefits:
- You ignore your current level of exhaustion.
- Your speed increases by 20 feet.
- You have advantage on melee attack rolls against a creature if at least one of your allies is within 5 feet of the creature and the ally isn't incapacitated.

You are immune to fire damage.

When you use this feature, two Bulezau (MToF pg. 131) burst forth from your burning flesh into spaces within 5 feet of you. They respond eagerly to your commands for the duration of the change. When you exit this form, you immediately attempt to reabsorb the Bulezau. The Bulezau instantly fall apart as ash and swirl back to you from up to 300 feet away. If one Bulezau has died or cannot return due to distance, you gain one level of exhaustion. If both are absent, you gain two levels of exhaustion and are stunned for 1 round.

Once you use this feature, you cannot do so again until you finish a long rest.