Elfen Lied, is it any good?

The gruesomeness will only get more frequent as the series progresses. There are some bloodless periods in the middle, where it is mainly talk and emotion, but since the story centers around people who use their invisible hands to chop limbs off, etc, if you don't like gory anime you should stop watching. Later, the killings take on a more emotional prominence rather than meaningless violence. Overall, the storyline is quite gripping and emotional so to me it is worth watching.