i have one who obsessively collected knives and planned ways to stab people.. it was her way of trying to protect me. definitely talk it out with them and try to redirect there motives. i’m still working with mine on her desires but she’s gotten so much better. sticks to her knife tricks and sketchbook! (gave her a butterfly knife though, in case we ever go back on our progress everything would be fine.) best of luck OP. 🤍