Bastard is a dark fantasy, action comedy manga from the eighties. Places, characters and attacks are named after various metal bands and songs. It's a story about four kingdoms, each holding a seal that keep the god of destruction in slumber. Of course some people with evil intention are trying to steal the seals and thus Dark Schneider, a loud, highly perverted, childish, dark wizard is summoned.
The anime follows the manga faithfully and the animation, voice acting and music are all great. Since it's an old story the pacing might feel off to some. There is a lot of fourth wall breaking and the series does not take itself seriously. Also be prepared for a lot of ecchi scenes. Manga readers will probably enjoy the anime because they know what they can expect. I'm not so sure about new viewers.