Sienna comes from long bloodline of hunters and werewolf and witches including shadowhunters and she moved to beacon hills to be with her family on the night of full moon and changes into a werejugar leaves the car and her parents kate argent and klaus mikaelson and attacks two teenage scott mccall and stiles while they are looking for a dead body in the woods peter hale the alpha is in the woods that night and see what the werejugar does to the two teenage by attacking them very viciously and aggressive and he has set his eyes on her his new target and Sienna left to find a den to stay in whike she stuck as a werejugar and scary of hurting her family and scott gotten bitten by the alpha that night and he tells derek hale about the werejugar that attack them the night in the woods when they was looking for half the body and that she was aggressive toward them or even more scary of hurting her love ones that she run off deep into the woods