Theology and Philosophy
The BrikVerse and all the places it interacts with are home to a staggering amount of creatures, many of them even sentient. With the planes teeming with life, and their own fates seemingly directed by outside forces, it is only natural that copious quantities of theological and philosophical beliefs and ideas would arise from a population struggling to make sense of it all.
There are many cults and religions in the Universe. Here are the more notorious ones.
Philosophy is endless in the BrikVerse, but often very simple. The great questions in life can be answered with the pointy end of a stick.