...And if I put a little reservoir into my knives to catch the blood of my enemies, I can use blood magic to curse the shit out of any that run away. Which would make the attrition rate for fighting me absolutely horrid, because anyone who gets cut and doesn't get seen by Voldemort himself, or maybe Snape, will just die. And that's a persistent threat coming from a spell I can manage wandlessly, in addition to whatever death I learn to spew from my wand. Ignore my knives and die to them. Ignore me and die to me. To say nothing of what it will be like to have Holly backing me up. Teamwork is always inherently more deadly than any solo act, no matter how dangerous.