I'm currently playing through a video game with eternal night.
The plants in that world have the ability to create a race of light-humans called Illuminators to shine for them.
The sun in the setting is just one mighty illuminater that has to rest for half a day and even then she can only do it for a certain radius.
But then it turns out the first half of the game was just a dream and the real world is even more fucked. The girl that was the sun died 300 years ago.