Was some time since I saw this, but I still think very fondly of it. This is one of those animes that'll go well with most people, there's not a abundance of cheap ecchi fanservice, braindead action or cliché characters, nor is it a pure drama but instead it's a fairly balanced mix.
The animation is suberb and soundtrack has some of the better j-rock songs I've heard. What really captivated me was the design and feel of the place where the story takes place, then again so did Beowulf (the original with Christopher Lambert) and that's a terrible movie.
My only concern with the series is that the story leaves quite alot of loose ends, although that helps to preserve some of the mysticism it's still unsatisfying. It's like a romance-anime without the relationship ever going past holding hands.
For some this OVA will be the best anime they've ever seen, for most others it won't. But it will prove entertaining for nearly everyone!
I'd give it a 8/10, it's a superb anime and something that any animaniac should've seen.