Death's Door

You open a door to the realm of the dead within 10ft of where you are standing. The door remains open for as long as your concentration is kept. If you lose concentration, the door closes immediately.  Every second the door remains open, one type of undead (randomly chosen:see below) emerges from the door and remains for 1 hour. However for every second the door remains open, your character loses one hit point. If your character reaches 0 hp they go down and the door closes immediately, however any summoned undead from the door remain until 1 hour passes.

D10 to roll for each undead:

1: Skeleton

2: Ghoul

3: Ghast

4: Wight

5: Ghost

6: Banshee

7: Drowned Assassin

8: Demilich

9: Giant Skeleton

10: Draugr