Which are your favourite characters?
-https://en.wikipedia.org/wiki/Dark_RiftDark Rift takes place far in the future, sometime after the events of Criticom. Gameplay spans three dimensions: the Neutral Dimension (where Earth is located), the Dark Dimension (home to demons), and the Light Dimension (home to energy beings). Although the creatures of the Dark Dimension are demonic, there is no indication that the inhabitants of the Light Dimension have any angelic qualities.
The crystal (the acquisition of which is the main motivation of the characters of Criticom) turns out to be the Core Prime Element of a Master Key, one which holds the power to all the secrets in the universe. The Master Key was found eons ago lodged in a spatial tear. When it was retrieved it burst into three pieces, sending two pieces into alternate dimensions, and widening the tear into the game's namesake Dark Rift.
