New Cryptworld Unsettling Power: Slam

I was recently reading through the old Pacesetter THINGS supplement and rediscovered an Evil Way discipline called Slam that I thought would make a nice addition to CRYPTWORLD. I've rewritten and reworked it as an unsettling power and added a little something extra - your CRYPTWORLD investigator might not be playing the piano for awhile!

Get out. GET OUT!!!!

Slam: This power allows a thing to forcefully slam shut any single portal (door, window, or gate) within a range of 100’ that it has previously shut normally. No amount of human effort can reopen the portal while the slam remains in effect, although the portal can be destroyed by extraordinary means (e.g. using explosives on a door or throwing a heavy object through a glass window). If a character is unfortunate enough to have their fingers caught within the slammed portal, they remain trapped until the thing relinquishes control of the portal and suffer a -20 penalty to DEX for 24 hours afterward. Use of this power costs 5 WPR per round of use.