Terminus

Creates an ephemeral pocket dimension known as the Terminus. This dimension overlaps the current plane of existence but remains unseen until its effects are triggered. The Terminus appears as a swirling vortex of darkness that engulfs the area within a 60-foot radius (with more casters focused on the spell, the larger the radius).

For each additional spell caster past the original 3 required, the radius is extended by an additional 20ft per caster.

While maintaining concentration on this spell, the casting creature can use a bonus action on each of their turn to activate the Terminus and unleash its effects. When activated, the Terminus imposes the following conditions on creatures within its area of effect:

• Spatial Flux: The space within the Terminus becomes unstable and unpredictable. Every 5 rounds, players must make a Dexterity saving throw, On a failed save, the creature is teleported to a random unoccupied space within the area (maximum of 55ft), taking 2d6 force damage on arrival. On a successful save, the creature can move as desired without being affect by the Spatial Flux until the Spatial Flux.
  
  
• Disjointed Time: Time within the Terminus becomes distorted and unpredictable. All creatures within 2/3 of the radius of the spell (except the Shrouded Desecrator) have disadvantage on Dexterity saving throws and initiative rolls.
  
  
• Darkened Veil: The area around the Veiled Tome becomes heavily obscured, and all vision, including darkvision, is blocked within it. Creatures outside 1/3 of the spells radius cannot see into it, and creatures within it receive the blinded effect.

By casting this spell, the casters gain the feat; 

Companion of The Shrouded Desecrator;  

Immortal Tether: While the Shrouded Desecrator is alive and present within the same plane of existence, a supernatural bond forms between the caster and the creature. This bond ensures that the casters health can never reach the precarious threshold of 0 hit points. Whenever your current hit points would drop below 2, they are instead treated as if they were at 10 hit points. This effect persists as long as the Shrouded Desecrator remains alive.