On a superficial level, the title is extremely fun, full of mostly naked chicks, muscular guys, epic level spells, ugly monsters, explosions that level mountains, girls hitting hapless men, as well as a weird mix of medieval castles and ruined high-tech cities. It comes off as someone has maxed out his JRPG characters and is now fooling around with mid-level fighters who think they stand a chance. So yes, it is like an isekai power fantasy. Only with very good production values for the time it was made and not the ugly CGI nonsense they give us today.
Fair warning, there is a plot, but it’s more of an afterthought. It comes down to a bunch of overpowered warlords fighting each other over who gets to rule the world, and everything takes place inside a hapless kingdom of mid-level fighters who desperately think they stand a chance in making a difference. They don’t; they are like the Z Warriors after the Saiyans went SSJ4. They are just there to gasp at the protagonist and his former henchmen blowing the crap out of their kingdom as they try to gather macguffins and resurrect the dark lord. And even then you will often forget that is what they are supposed to do since the focus is given on the (fairly shallow) drama Dark Schneider and his generals have going for centuries. Nobody is a cardboard, but it’s not like you can call them deep or something. It plays out like a satire of your typical heroic fantasy campaign, where every major fighter is deep into epic levels, very immoral, lawful evil, and permanently horny (there is constant sexual harassment and what many today would label attempted rape). It taps into your lizard brain and doesn’t let go. Oh, and it does it with actual effort and not the half-assed CGI nonsense of today.
Down to it, I liked it for how proactive the main character is. Yes, he is a perma-horny bastard who loves to molest women, but he is not your typical indecisive harem lead, not your nerdy pacifist, and not your typical boyscout protagonist who wants people to be nice to each other. He is the ultimate power fantasy, with none of the moral hypocricy that usually comes with shonen protagonists. Obviously, for the same reasons he can rub a lot of viewers the wrong way. You see this last bit mostly in the newer version where everyone was so triggered with his attitude. But there is a different review for that and it refers to a show that came out at a far more sensitive time. For a 90s OVA, Bastard with double exclamation point gets two thumbs up from me, for it’s the best thing they could offer you without a shred of hypocrisy.