So I've been playing with a lot of the least attractive choices in the Dark Eldar codex, and I figured I would give Mandrakes a try again.
And to my surprise they have been awesome. They do need to start with a Haemonculus for the shooting attack to be activated from the beginning. But it's awesome to Outflank them. With all that S4 AP4 shooting and 5+ inv & FnP they are a serious threat, especially with a Heami with a Liquifier Gun.
They have been my MVPs in every game they have been in!
Here they are, my first unit of ten: