Location from Undertale / Deltarune by Toby Fox
Geysers of dark energy that create entire worlds from the objects around them — and someone keeps opening new ones.
Dark Fountains are Deltarune's central plot device. They create Dark Worlds by transforming the objects in a room into living Darkner civilizations. The supply closet becomes the Card Kingdom. The computer lab becomes the Cyber World. Each Dark Fountain is created by someone (possibly Kris during their soulless episodes) and must be sealed by the heroes of prophecy. The prophecy warns that if too many Dark Fountains open simultaneously, the 'Roaring' will occur — an apocalyptic event. Ralsei knows more about this than he reveals.
Pillars of dark energy erupting from the ground, transforming enclosed spaces into vast Dark Worlds. The fountain itself is a vertical stream of darkness at the world's center. Sealing one returns the Dark World to its original form — a closet, a computer lab, an ordinary room.
Also known as: The Fountains, Dark Geysers