This has got to be one of the most balanced Shounen of all times.
The main isn't that dumb or foolish/naive nor is the female lead the constant damsel in distress or the always bashing violent type. All the characters are solid with strong realistic motivations and the story is well paced. The "antagonist", or the closest thing to it in the story, as there isn't a truly main one is also very interesting.
Sometimes I founded myself rooting for Papillon throughout most of the episodes and Victor had every reason in the world to behave the way he did and his draining of life energy wasn't really his fault either. The abilities were also unique in their blending of both the scientific and fantasy elements.
I want to know, for those of you who've seen or know of the series, why is it so underrated?