As is the case with most obscure Anime I watch, I find it irresistible to review once I see the lack of information on it available online. As there are no other reviews for this OVA I'll sum it up for you, as well as expose my personal feelings towards it. As you can see I'm under the false impression that any form of human being will eventually stumble upon this.
In a world where humans, ghosts and ogres co-exist not-so-peacefully a solemn warrior armored with his infamous sword travels across the world in search of monsters to slay. Under the vague impression that he'll achieve a humanity he longs for once he's slayed every ogre currently inhabiting the world, the lonely swordsman stumbles upon many obstacles and characters on his way towards his goal, and these little adventures are what comprise the main storyline in Ogre Slayer.
The concept is simple and tedious: ogre kills, ogre dies. Episode 1 plays out exactly to audience's expectations with gratuitous nudity and plenty of gore to behold. After that, the story gradually improves and reaches its prime right around episode 3 where it actually turns into something good. Then it disappoints once again. Overall, the story in Ogre Slayer escalates into a love/hate affair; it has no business being good (and for the most part it isn't) but when it actually tries to reach beyond the frames of sex and violence it's actually able to achieve some genuinely good storytelling.
By contemporary standards, the animation found in Ogre Slayer would radiate mediocrity, but in modern times it's heavily flawed. Moments of passivity are relatively decent to look upon, but as soon as movement initiates you start to realize the numerous short-cuts they take, and a budget that can't have been very high.
If I am to compliment anything though, it would be the actual ogres. They are definitely designed to be as gruesome and disgusting as possible, and in that sense the character designers really succeeded.
A category that's very hard to rate; on one hand, the concept of a solemn and lonely warrior slaughtering his own kind is very unoriginal, but on the other hand it probably wasn't at the time of production. Still, as far as compelling characterization goes, Ogre Slayer has little to offer.
The protagonist is far too contracted, the minor characters are only there to compliment the background with gore, and overall the development is pretty much non-existent.
The voice acting is surprisingly solid, and while the soundtrack may be extremely generic it fits the tone of the story pretty well.
I expected pure garbage and got a pretty bad, but still tolerable OVA. If you enjoy gore, monsters and Anime from the 90's, then I can recommend this. But chances are you still won't enjoy it very much.