D'aww! Love these two, the spirit of Winter and the first ever Guardian of Childhood. Nightlight is a spirit of few words, but he's always such a calming, heroic presence. You always feel safe when he's around, even when he's not feeling his best. Jack is a very vocal spirit, and sarcastic too, but you can always rely on him to keep things lighthearted in the darkest of times.
I do think that, due to Jack, we'll never see Nightlight in the movies...Which makes me sad. ;.; But likely explains why I love both of them so much! Such fun characters. And lovely drawing of them both! ^^
Nightlight is described as a spectral boy who is actually the Guardian of the Man in the Moon and his longest best friend. Ever since the MiM was a baby, Nightlight has been his loyal bodyguard. He hardly talks, glows, and wields a staff tipped with a dagger made of diamond. During a heated battle, he flew (dagger first) at Pitch and impaled him, which sealed Pitch away but was coincidentally sealed within Pitch's heart. Their fight signified the end of what was known as "The Golden Age". It's mentioned that he looks lonely, is afraid of growing up (if he can), and is fiercely loyal to his friends.
I think that's mostly it...he also has a "perfect" laugh and is able to walk and sit on clouds. In a sense he's a lot like Jack.