Still too many questions remaining at the end. But all is perfect in the series. The plot, the characters, "Lilium" song (i discovered it before the anime itself ^O^ I suggest you to pick it up==>Konishi Kayo & Kondoo Yukio "Lilium" ), the emotions all along the episodes... Only the ending song is a bit irritating and has nothing to do with all the rest. And perhaps the series itself is a bit short. But I've loved all what i've seen.
Then, we don't have to forget the psychology and the sad stories of all the characters (all those cute girls too^^)It's quite like nobody had a happy life. A bit of nudity (but all without sexual contents, don't worry). Not for kids although because of all that blood and explosing bodies^^
I m not telling the plot... Just watch it. It won't take too long though.
What else? Elfen Lied is a little Japanese jewel XO I'm waiting for the second season (hoping that there will be one... but the end seems to say us "ha ha ha, it's not yet the end!!!")
No, no^^ I m not putting any spoiler. Enjoy!