Light and darkness, they are a balance—one that must always be maintained. Light will always create darkness in it’s path, as darkness will always bring light. The two can not coexist without the other. Darkness doesn’t have to be your enemy, it can be a very deadly force or the most powerful shields in existence, it all depends on ‘who’ wields it.” ~ combination of quotes said and/or implied by Master Xehanort all combined into one.
 
In this case, Luna reminiscences about her time as the dark entity Nightmare Moon. That she can still feel the darkness laugh down at her.