And what does Luna do when she's "sick"? I'm glad you asked. She writes and sings her own ~slightly terrifying~ songs:
Luna's song starts out sweet and very PG: "Momma lo-love you all the day. All day we la-e-o day. Momma loves you ... Momma's gonna put you to bed."
But the next part of Luna's seemingly innocent tune takes a shocking twist: "Momma loves you as much as she loves...ALL THE DEADS, ALL THE DEADS. ALL THE PEOPLE ARE RED O DEAD, RED O DEAD, RED O DEAD. ALL THE PEOPLE RED O DEAD, RED O DEAD, RED O DEAD. ALL THE PEOPLE ARE RED..."
So there you have it: a very "sick" Luna, the next singer-songwriter of her generation.