everything is light (or energy). this is why kundalini can be so beneficial but also terrifying to some. all of our karma and negativity is retained in the form of energy. our thoughts and beliefs, including the ego structure is energy. when kundalini is released it goes where it wants and will find its way through this energy. it can be disconcerting to experience this. the kundalini does not explain what it is doing, but you can be sure that when that energy hits a block it is some illusion, belief, karma or fear. just yield to it and surrender.