Lich Transformation 2 Boon: Rift to the Dreadscapes

You gain the ability to open a rift to the Dreadscapes. As an action on your turn, you can choose a point within 5 feet of you to open the rift. Once opened, the rift stretches out from that point to a 12-foot-radius sphere. When a creature other than you enters the rift's area for the first time on its turn or starts its turn there, it must make a Constitution saving throw against your Transformation DC. On a failed save, the creature suffers 10d10 necrotic damage, or half as much on a successful save. Undead creatures are immune to damage from this ability. The rift remains open for 1 minute but closes if you become unconscious. Once you use this ability, you cannot use it again until you complete a long rest.