Ahhh that was a goood sleeeeep! 
Now for the dark side, well dark side includes lots of things, to be well atuned for the dark side there is one thing you need a lot: negative emotions~ And I believe Nai has enough of those for the moment and in general. Sure she isn't an outright villain, but she can be vengeful. To begin with as Fox said, Nai is out of control when she snaps so she is often a lot of bark and little bite, unless she starts biting when she was enraged :3 then it's lot's of explosions.