Demise Subrace

Ability Score Increase. Your Constitution score increases by 1.
Explosive Growth. Starting at 3rd level, You absorb all light surrounding you, creating magical darkness in a 10-foot radius centered on you. This darkness lasts for 1 minute and moves with you. For you it is considered non magical darkness.
Once you use this trait, you can't use it again until you finish a short or long rest.