Bastard!! Ankoku no Hakaishin (ONA)

The two main characters have a very similar relationship dynamic (kind girl with control over a powerful demon after breaking the seal on him). Both shows are also action adventure in a fantasy setting with bits of comedy and serious/emotional moments. I'd say anyone drawn to these aspects and likes one should give the other a shot, though "Bastard!!" is certainly less appropriate than InuYasha due to nudity and darker themes. 

Both are dark yet tongue-in-cheek fantasy stories based off late 80s shonen manga with a cast full of manly men and a surprising amount of women who can hold their own as well. They are also packed to the gills full of western music and pop culture references and influences. 

Within the anime community, Bastard‼ and Claymore are considered dark fantasy series, in which dark refers to violence and/or atmosphere. Within the literary fantasy community, both series would be better described as part of the sword and sorcery subgenre. Claymore is definitely a better anime than Bastard‼, which wastes no opportunity to include ecchi content. That being said, some Claymore fans might enjoy Bastard‼ for its trashy qualities.  

I would suggest something like Berserk (manga and anime) if you liked Bastard!! Both are really good seinens in my opinion. The art (even tho not as detailed and more so talking about the anime) - it reminds me of Berserk, along with just the world this is set in. However the characters relationship reminds me more of Inuyasha with Kagome haha.  

Powerful beings from centuries ago are brought back to face imminent threats that could destroy their worlds. They are arrogant, egotistical and self-centered, they couldn't care less about what's going on, and would rather do as they please, but end up helping out of obligation. Sealed into the body of a child, both of them transform into adults in order to fight with the help of a teenage woman, who also keeps them in check whenever necessary. Sometimes they also handle sacred weapons that hold spirits within them. These fantasy shows have a similar vibe going on with the main characters and the general setup. They differ in their desires, with Dark Schneider being lustful for hot women, and Zenki being of the gluttonous kind regarding the Seeds of Evil. The settings are also different with Bastard!! being medieval fantasy-themed and Zenki taking inspiration from Hinduism while being set in modern times, though the cast gets sent to a feudal Japan era for a handful of episodes. Despite both having the Ecchi tag, Zenki is very tame regarding suggestive content, and even then it's only in the first few episodes, whereas Bastard!! does contain significant levels of nudity all the way through, especially in the 2020s anime. read more 

Both shows deal with an ancient, powerful figure from the distant past reincarnating in the present, dealing with figures from his previous life as he tries to get his former glory. Both female leads are also voiced by Tomori Kusunoki. 

From the first episode, you will know that Bastard‼ and Cross Ange are aiming for peak trash quality. Bastard‼ excels at finding plot relevant ways to balance echhi heavy scenes with bloody violent battles to create a spectacle. Cross Ange excels at layering ludicrous characters and storyline while inserting echhi scenes to create an entertaining trainwreck. Both series pushes the boundaries of their genre to the adoration of its fans.  

Bastard‼ and Berserk are adult fantasy series with graphic violence, but from different subgenres of fantasy. Berserk is a serious, medieval fantasy anime that understands warfare. It might be an incomplete adaptation of the manga, which barely covers its long narrative, but this arc is a great anime. Bastard‼ is a comedic, sword and sorcery fantasy anime that never misses an opportunity for echhi despite its violence. It is a trashy series that targets a specific audience and it does this very well. If you have the correct expectation then this might be a recommendation for you.  

Fantasy is a well established genre in anime, but Bastard‼ Heavy Metal, Dark Fantasy and Record of Lodoss War is best described as part of the sword and sorcery or heroic fantasy subgenres. Some may consider their storylines as stale or generic fantasy, but fans would consider them as classic fantasy stories representative of the early 1990s. Bastard‼ was also part of the wave of anime titles with extreme violence and sexual content from the 1980s and early 1990s, even though this is a new adaptation. If you consider yourself a fan then you'll enjoy this recommendation.  

In the 1980s and early 1990s, there was a wave of anime titles with extreme violence and sexual content. Ninja Scroll is the most well known title of this trend. Bastard‼ Heavy Metal, Dark Fantasy is a remake of a title from this period. While many people continue to watch Ninja Scroll for its classic status, Bastard‼ and Ninja Scroll appeal to a very specific audience. If you count yourself as part of that audience then you should definitely watch this anime.  

Oh baby that's the good stuff. 80s shlock at it's finest but with a new coat of paint. I can't possibly see why you wouldn't watch both of these shows right now unless you're too young to enjoy something that's completely stupid and insane.