There is a mod out there that lets you cast a spell to increase or decrease the darkeness at night and I believe it is based off of URWL(Ultra Realistic World Lighting) . I cannot find it, does anybody have the link?

I believe you're talking about the IMAGINATOR, which allows you to have a massive amount of control over various visual effects in Skyrim.

It's not IMAGINATOR or URWL. It's a standalone mod that uses the feature of Imaginator to make nights darker.