1. Maleficent – She might be trapped between life and death
2. The Wraith or someone else Aurora and Mulan met while they freed Philip’s soul.
3. The Sandman – He is the brother of death, bringer of sleep and dreams and in E.T.A Hoffman’s version a very horrifying character.
4. Someone connected with the origin of the sleeping curse. Maybe Odin.
These are the first four things which came into my mind and it would be very interesting if that person is someone we haven’t met yet. But if I would have to choose I would guess it’s Maleficent.
Well, I’m pretty sure we will find out more about it in the future, but I’m not sure if the writers want to tell us about it in this season.
“There were thousands and thousands of forms of joy in the world, but that all were essentially one and the same, namely, the joy of being able to love.”