Okay! Her power comes from the poison she drank to save the Arch Duke, it had seeds that had been known in an ancient time to be a flower that devoured a demon like monster. Before she could control that monster, it would manifest as the thorns and flowers and a ghost like resemblance of those around her. Once she made a contract with it should could not only use the thorns to still tie people up (and fling them - that's the fun part hehe), the monster can now manifest to do her bidding (though instead of taking on the vision of one of the Arch Duke's knights, it's a teddy bear - too cute!).
Ohhh ok, that makes sense! Thank you for explaining!
I'm a bit confused about her magic, I remember it was thorns, now it's just darkness... It's a bit weird how it just changed, it was more beautiful before...