Nightmare moon, Sombra, Tirek, all names created and born from darkness. Chrysalys, Discord, and many others evil by breed or by ignorance. The ponies where growing yes, understanding and learning. But did they truely understand what Darkness was? More importantly.. how darkness changes a person? It is widely belived in the hearts of ponies that Darkness is a force of negativity and thus must be destroyed, but is that really the case? Mathias Cronqvist himself pondered the question often, and as his castle rose in this new land, he could not help but hear the question again in his mind. Perhaps this new world would hold the answers his soul and mind sought.
One of two castlevania stories to come to mind that crosses over with My little pony. As for the tags ill fix those later im sure if they dont fit after all.