The layout for most of the characters is well done, they contrast each other nicely and cover pretty much any attitude known from modern animes/mangas. Ranging from egoistic, funny, morally over desperate, lovable, childish, weak to downright evil, fanatic and insane.
And there are a lot of characters, by covering any major concievable aspect, the anime fails to give each of them a compelling background-story or enough "prime-time" to fully develope. Most of them dont have necessary influence on the main story.
The first part of the story unfolds the background of the main protagonist Saya in a lengthy of "The Twelve Kingdoms" reminding stilistic way, the later consists of a standard apocalyptic scenario carried by the antagonism of Saya and her counterpart Diva. By the time the anime ends over a dozen substories have been created and most of them wont be finished. The end is horribly designed and features "deus ex machina" in all its glory. Also the entire story could have been told in around half the episodes, without any noticable loss.
But my main problem with the anime is not it's story. Blood+ is completly, fundamentally illogical. Each anime has a set of rules under which it operates.
Like "vampires burn if they go into the sun", "Shinigami can't die, they just go back to the realm of dead" etc. Blood+ violates his own set with a to me yet unkown consistency.
The entire story is based on a fundamental rule "The only one beeing able to kill the vampire-like-creatures is Saya", it adheres to this rule for just a few episodes, than ignores it, states it again (and keeps stating it until nearly the end), gets proven wrong (severing the head/burning works just fine), but ignores this by saying humans are not able to do this, although they have already done it. This continues by proclaiming those creatures can't kill each other, which gets also silently changed. New rules are introduced, old ones are forgotten, reawakend and changed just to proceed the storyline. In my oppinion unacceptable.
