Symphony of The Rotten Wombs

With the ethereal voice from far lands, your mind becomes consumed by a darkness never seen. Your eyes turn to gaping blackholes; your feet, your whole body feels numb, you perceive but can not comprehend. You hear, and hear only the ethereal symphony through your tongue, as you unconsciously sing in tune with that divine melody as everyone and everything you've known rot away behind the darkness of your eyes. You smell only the sweet, sweet smell of rot and rust, as your body gets heavier and heavier, until there is but the darkness.

The caster starts to chant in an incomprehensible language of unknown origins. For the duration of the spell the user Restricted and Incapacitated -unless it is to end concentration.

Starting from the moment the spell was cast, every living creatures that is alive in a 40 ft cylinder, centering the caster, takes 5d8 Necrotic damage per turn, becomes vulnerable to piercing, slashing and magical damage of any kind -except for Psychic, Radiant and Necrotic damage- and has disadvantage on Constitution, Dexterity and Strenght saving throws; as well as reducing their movement speed by 15 ft. Plants, objects, Undead and Constructs takes twice as much damage (10d8). Weapon attack deals -1d8 of its original value. The casters Temporary Hit Points are ignnored, and takes 2d6 Necrotic damage per every turn the concentration is ongoing. The concentration ends if the caster dies, breaks the concentration, is put to sleep, or if the casters hit point drops down to the pre-determined limit (2d8+spell casting ability modifier). The caster cannot have advantage on concentration saving throws.

 Per every level above 6th gain +1d8 to damage towards outside, +1d4 to weapon damage penalty and +1d8 to damage taken from maintaining concentration. Breaking the concentration by choice result in caster to lose its action and movement speed for that turn.