A Gargoyles/MLP Crossover? BRILLIANT! Plus, Lexington is my favorite of the gargoyles because, like me, he's small but knows the value of knowledge as a weapon. Anyone who's seen the show Gargoyles knows what I mean.
Luna Eclipsed showed her briefly assuming that form and transforming back at will, though it's not made clear whether this is a genuine transformation or if it was just a simple illusion she performed (though spitting out the fake fangs after changing back might suggest the latter).
It is pretty sad when you consider how it's pretty damn true. I mean, it's been proven she isn't always just sleeping during the day. Luna could have taken the effort to get to know her subjects more instead of just moping about how "nopony is appreciating my night" and all that schtick.
She probably did make an effort. But social anxiety disorders and subconsciousness about her sister, and the fact many ponies probably did simply like Celestia more, will have continued her self destruction. A lot of the problem is that Celestia probably didn't realize her sister's psychological dilemma, and Luna probably didn't take proper care of herself or to solve the problem either. Suicide disorders often could be solved by simple actions, but people become unable to bring themself out of the depression to end the cycle.
And of course, all the Luna fanboys will rally in her defense, saying how everything is all Celestia, the ponies, etc's fault and never hers, never wanting Luna to take any responsibility for her own actions.