Illevaere's Transformation

Chosen of Caena

The Chosen of Caena represent the epitome of dedication of her followers. When a follower is ready, they will take the poison Erebosbane, a deadly concoction of herbs brewed together into a very potent and often lethal creation. While imbibing of the concoction would kill most outright, worthy followers of Caena will slowly absorb and transform the poison in their system, in the process transforming their own body.

Erebosbane

Erebosbane is a concoction of poisons whose methods of creation are only known by the faithful of Caena and it is considered to be holy and its use outside of testing the faithful is considered profane.
If a non-follower of Caena, or a follower under 10th level were to imbibe Erebosbane, they would have to make a Constitution saving throw (DC 30) against poison. A successful save would result in the imbiber receieving the Poisoned condition for 21 days. A failed save would also give the Poisoned condition for the same time, and the imbiber would immediately drop to 0 hit points and be dying. Every 5 points that the saving throw is missed by counts as one failure on death saving throws.
Those of sufficient dedication and level who take Erebosbane have the poison within their systems for 21 days as their bodies try to absorb and transform it, changing to adapt to the poison in their system either for better or for worse.

Dedicated Followers

Dedicated followers of Caena who imbibe Erebosbane must make a Constitution saving throw (vs. Poison) after each long rest. The base DC is 20, with the following modifiers:

-5 to the DC if the imbiber is a cleric, druid, or paladin dedicated to Caena.
-1 to the DC for every level above 10 that the imbiber is.
-2 to the DC if the imbiber took their long rest at a shrine or temple dedicated to Caena.
If the first saving throw is failed, the imbiber’s body rejects the poison and the imbiber is immediately reduced to 0 hit points and dies.
After the initial save, a failed saving throw at the end of each long rest means that the imbiber has the Poisoned condition until the end of their next long rest. Over the course of the 21 days, the character needs to track their successes and failures to see if there are more successes or failures. As soon as 11 successful saves or 11 unsuccessful saves are reached, the poison is absorbed and the body is transormed.

The Chosen

Whether someone succeeds on the majority of their saving throws or fails on the majority of their saving throws while absorbing Erebosbane makes no difference the acceptance of them as one of the Chosen, as followers of Caena understand how fickle the Mother of Plagues can be. The only difference is how their bodies have adapted to the Erebosbane poison that is within them and whether they have received the Mother’s Grace (by passing the majority of their saving throws) or the Mother’s Torment (by failing the majority of their saving throws).

Mother’s Grace

Those fortunate enough to have received the Mother’s Grace are immune to both the Poisoned condition and poison-type damage as well as any magical and non-magical diseases. This includes damage and conditions that would be received through the spells contagion and ray of sickness.
Those booned with Mother’s Grace can further heal the Poisoned condition or any disease from others by absorbing it themselves by touching the target. For each condition or disease absorbed, the Chosen loses 5 hit points from their maximum hit points. This loss persists until the Chosen completes a long rest, after which, the Chosen recovers 10 hit points to their maximum hit points. A Chosen dies if their hit point maximum is reduced to 0. This healing can also heal disease or poison affecting animals (such as rabies) or plants (such as blight).

Mother's Torment

Those who suffer Mother’s Torment are affected by the Poisoned condition as soon as they finish a long rest. This condition persists until it is removed, either via magic (such as a lesser restoration spell) or through alchemical remedies, requiring an alchemy/herb kit check at DC 20. However, the Poisoned condition will return at the end of the Chosen of Caena’s next long rest.
A Chosen with Mother’s Torment does not suffer alone. Once per long rest, the Chosen of Caena can cast both Contagion and Cloudkill as 5th level spells without expending a spell slot.