If you're looking for anime similar to Bastard!!, you might like these titles. All recommendations are made by Anime-Planet users like you!
Negishi Souichi always dreamed of joining a trendy pop band, so that he could perform music like that of his idol, Kahimi Karie. In order to realize his dream, he decided to leave the country side and his loving parents to study in Tokyo. And after graduating, he does manage to join a band... but not the kind he was expecting! As lead singer of the death metal band Detroit Metal City, under the stage name Krauser II, he is made to perform loud songs filled with obscene lyrics - a far cry from the songs he used to write in school. But despite the fact that Negishi hates DMC's music, the Krauser side of him will do anything to put on a good show for his fans... even if it means making Negishi's life a misery!
DMC and Bastard have one big theme in common, metal. It's pretty clear why DMC is a very metal show, DMC is the show that Metalocalypse should have been. And Bastard is also a very metal show, the main kingdom in the show is called Metallicana, and there are plenty of other metal references. Both of these shows also have a protagonist who has a double personality, with one personality being ridiculously unassuming and the other being ridiculously over the top. Both shows have humor (though DMC is much funnier) and are perfectly suitable to show kids if you want the kids in question to have nightmares. Bwahahahaha.
Both OVAs feature dumb comedy, metal references and dual-personality protagonists: one personality being kind & modest and the other - ridiculously over-the-top & immoral. The differences are the setting, the art style and the pacing (DMC is more dynamic than Bastard).
In the revolutionary Meiji period, Japan is undergoing enormous political change. It is a time when vagabonds and terrorists will use any method to prevent the modernization of their country, even if it means trampling on the innocent in the process. In such a time, Himura Kenshin, a wandering samurai, has dedicated his life to protecting the weak and desperate peasants from those who would oppress them. However, Kenshin has a dark past which threatens to destroy the values he is fighting for. When he meets his new friends Kaoru, Sanosuke, and Yahiko, and tries to build a peaceful life with them, events conspire against him. Can Kenshin overcome the demons within and without, and finally ensure the peaceful future that Japan deserves?
Kenshin is perhaps Japan's version of European Medieval times. In an age of great conflict, Kenshin uses his sword to defend the weak. His reputation as a blood-thirsty assassin precedes him everywhere he goes, as many formidable villains seek to test their skills on him. Sword fighting plays a huge roll in this anime, which is loaded with action, and deep plots. Kenshin is one of my most highly recommended anime series for anyone.
Kagome is a normal high school girl who falls into a well, transporting her back in time to the feudal era. Upon her arrival to this world, she mercifully unleashes Inuyasha, a half demon. As if this isn't enough, she also discovers that she is the bearer of the Shikon no Tama, a jewel of great spiritual power, a jewel which has just shattered into a million shards. Now, along with Miroku the priest, Sango the demon hunter, and Shippou the mischievious fox-demon, they must set out to find the Shikon shards and defeat the evils of the demon Naraku.
The earlier portions of Inu Yasha, where the main characters didn't get along quite so well, remind me of Bastard--basically, having the only guy with the power to fight off the baddies chained to the main character 'against his will.' Bastard is considerably darker, but both have a kind of 'demon on demon' fighting that you might find interesting.
Arslan is the prince of the Palse kingdom, a beautiful country which is located amidst the sand dunes. Peace in the land of Palse is soon disrupted when the Lusitanian army attacks, led by a man known as Silvermask who claims to be the true heir to the throne. After fleeing his home under siege with his only remaining general Daryoon, the young prince travels from kingdom to kingdom, gathering the support and loyalty of new friends, including Gieve the minstrel, Pharangese the warrior priestess, and Narsus the master strategist to help him reclaim his beloved Palse.
Thousands of years in the future, the world is overrun by demons and vampire lords. Doris, a young girl, has become the target of the great vampire lord Count Magnus Lee, who wants her as his plaything. After being bitten by the Count, she seeks the help of D, an elite vampire hunter, who decides he must venture out to slay the Count and his demon underlings to save this girl in despair.