The following is a mystery from the shadow magic system of the Tome of Magic, you can learn it at 11th level.
PnP Description:
Summary
Pass Into Shadow
Initiate/ebon roads
Level/School: 5/conjuration (teleportation)
Range: touch
Target: creature touched, or up to eight willing creatures joining hands
Duration: instantaneous
Saving Throw: Will negates
Spell Resistance: yes
You break the boundaries between worlds, opening a path into the Plane of Shadow.
This mystery functions like the spell plane shift, except that your destination or origination must be the Plane of Shadow.
My interpretation:
Summary
Initiate/ebon roads
Level/School: 5/conjuration (teleportation)
Range: Touch
Target: Creature touched
Duration: Instantaneous
Saving Throw: Will negates
Spell Resistance: Yes
You break the boundaries between worlds, opening a path into the Plane of Shadow.
You banish a single foe to the Darklands in the Plane of Shadows, with no possibility of return. You must succeed at a melee touch attack. If the target fails the will saving throw, its sent straight to the Darklands, falling into the middle of the Bleak Sea, a vast sea of foul black ichor formed from negative energy that slowly kills any living thing that contacts with it.
There are other 2 mysteries that involve teleportation, one works like dimension door(teleport to a location in sight) and the other works like shadow walk(i made a teleport system for this that uses waypoints) so, i ran out of ideas for this mystery i got the idea to use it like that from the Epic spell Damnation. Phantasmal Killer which is also a save or die spell of level 4th so it may be ok.