Umineko

Short for Umineko no Naku Koro ni, a badass murder-mystery anime series aired in Japan between July 2nd and December 24th, 2009. It deals with the events that unfold on the fictional island of Rokkenjima when the head of an incredibly rich family calls the entire family to the island to discuss the distribution of the family's wealth in the event of the head's death. However, mysterious deaths start occurring the first night on the island, with everything somehow tying into the legend of the "Golden Witch," Beatrice -- who is rumored to have been a close acquaintance of the family head. Battler Ushiromiya (that's right, his name is fucking BATTLER. It doesn't get much more badass than that), the protagonist of the series, refuses to acknowledge Beatrice, and instead insists that all of the murders can be explained using "real" and "physical" means - even those that seem to be impossible for humans to have accomplished. Long story short, everybody dies (at least everyone who was on the island), more witches appear than I can even count, and Battler eventually becomes a sorcerer who wields a badass SHINY GOLD LONGSWORD that lets him SPEAK IN BLUE-, RED-, AND EVEN GOLD-COLORED TEXT. Originally a series of visual novel games which were later adapted into an anime. Made by the same people responsible for Higurashi.