[Location: About a kilometer away from the Coast city, in the vicinity of the portal area!]
The dark red portal slowly expanded, first from the size of a fist to big enough for a child to enter. And then slowly to the size of a man, and then enough for a house to fit in. It kept expanding slowly without showing any signs of stopping until it reached the size big enough to cover the entire city on its own.
While the top of the portal was at the same point where it began, in the sky far above the ground. The bottom part, reached to the ground, showing a completely different strata on the other side of the portal.
Contrast to the white soil on the mortal plane, the inside of the portal was covered with dark gooey and muddy soil, as if the entire area was covered in a dirt swamp. If the trees were lush green here, the leafless trees inside there were filled with thorny branches, with traces of blood red rocks growing within them.