If the wielder sees an a creature die the wielder may choose to absorb their essence as "soul essence" that can be stored inside the chalice and used for magical purposes. The wielder can hold up to a maximum of 20 essences including their own soul. If the chalice is full upon death and the wielders soul is absorbed into a full chalice the artifact is completely destroyed along with the soul. Upon consumption their essence is released from the chalice. 

Corruption Levels

1. Taint- Radiate a field of compulsion (30ft radius) creatures inside make a DC 18 wisdom saving throw. All who fail feel an overwhelming urge to obey. You experience paranoia you no longer have advantage in insight if you did before. If you didn’t you have disadvantage. You may however experience visions of hidden agendas against you. 

2.Blight- Difficult terrain doesn't impede movement, as a bonus action the user can use Gaseous Form. One random physical manifestation will change the characters appearance. And a random physical manifestation of corruption will change the wielders appearance with each sip past level 2.

3. Plague- Dragons defeated under the wielders control will rise as loyal undead minions, you can control a number of undead dragons equal to twice your proficiency bonus. At level three once per year you must make a DC 25 Wisdom save or be tempted to drink from the liquid furthering the corruption. This isn’t curable by ordinary means.

4. Wretched Vessel- As an action the wielder can spend 1 essence to create desolate land up to a 10 mile radius. The wielder gains resistance to all damage types. the wielder may step into shadow to teleport into shadow on the same plane of existence. Once per king rest the wielder must make a wisdom saving throw of 23 or they must go to war in an attempt to conquer or completely destroy land.

5. Abyssal Avatar- The wielder's alignment changes to chaotic evil. The wielder sheds dim light in a 10 ft radius and darkness in a 20 ft radius beyond that. Hostile creatures in the darkness take 1d8 necrotic damage at the start of their turn. Hostile creatures in the light that is shed will take 2d8 radiant damage at the start of their turn. The wielder may spend 10 essence to unleash an apocalyptic event in a region (the moon and sun disappear from the sky for 7 days) for every minute of the day of the seven days there is necrotic rain that does 10d10 necrotic damage each turn a creature doesn't succeed a DC CON save of 24. All vegetation withers and dies. When the wielder dies at level 5 their soul is absorbed by the chalice unable to be released by ordinary means.