When a miracle is worked, when a God turns His attention to the mortal realm, the mortal realm is irrevocably changed by the Divine Presence. When this takes place through a living being, they become the Godmarked. Ever with one foot in life, and one foot in the realm beyond, they are emotionally and physically altered - always in a fashion that reflects the nature of the God that they have channeled - One who channels a God of the Winds may forever have a breeze lifting their hair, while a Goddess of Anger may blacken the skin and strengthen the body.
A massive iron key - 2’ length, 20 lbs forged with demonic faces from the bones and horns of demon-lords. When used with a massive portal - carefully built according to documents found in powerful books of evil knowledge, it will open into the realm of demons and allow them to flood into the world. The applications of this item for villains are obvious. Mortals touching this item are subject to [Effects_of_Touching_Powerful_Evil_Artifacts]
You come upon a ruined building in the back section of a city park (or other out of the way area of the city). The ruins are fairly overgrown. All that is really standing is a doorway and its frame. If you pass through the opened door, you travel to a different world. If the door closes, there may not be a doorway back to get you back.