I've watched the entire Elfen Lied series between yesterday and today. All I can say is: HOOOOOOOOOLYYYYYYYYYY SHIIIIIIIT.
This, my friend(s?), is a multi-faceted "holy shit."
On the one hand, Elfen Lied is a beautiful story with highly believable characters (even the mutant characters, the diclonii) and a major appeal to us X-men folk due to the whole Mutant vs Humans thing.
On the other hand... There is no way in any language to express how incredibly fucking violent this show is. The main theme is the overall inhumanity of humans, focusing highly on violence against women and children, and boy is this show inhumane. Death? Plenty. Casua