Has it ever bothered anyone how boorishly griffindorian Voldemorts approach to sieging Hogwarts was? I mean seriously, he's all like lets just knock on the front door, bring an "inconspicuous" army, and then announce our presence asking people to give up someone he already knows they won't betray. Before battering down the wards, and charging straight at the monumental defenses of Hogwarts that he has to know exist. He spent seven years of his life intimately studying hogwarts and its magic, I mean come on people he found the room of Requirement, and the Diadem of Ravenclaw. Not to mention his return when he was applying for the dada job he would've been seriously more experienced then and would have noticed more subtleties in the wards. Not to mention his other Mistakes in his career as a "Dark Lord" seriously when hiding the anchors to your soul, must you choose such extravagantly obvious objects only to hide them in places you are intimately familiar with. (side tangent: why in the hell would you split your soul into seven pieces, do the math say six of them are destroyed that would be six fragments pulling you toward death and one anchoring you I wonder which group has a stronger pull. And you can't argue that they return to him or his countenance would have improved throughout instead of deteriorating as they destroyed the Horcruxes, and the fact that harry encountered the soul of voldemort when he "died". Furthermore when he did all his traveling around the world did it ever occur to him to hide a bloody goddamn Horcrux, just one outside the goddamn country. They never left the bloody British isles the entire time. So nice of you to set up such a nice and localized scavenger hunt for Harry and his companions. It would have been far better to chose a inconspicuous item with no connection to him at all at random, and then hiding it in a similarly chosen location) Seriously though he would've been better of using the secret entrances he already knows, (see argument above) to sneak in a few rogue elements at a opportune moment, say for example werewolves (who he was allied with) inside the castle during the full moon. not enough to kill everyone inside just enough to force the professors to congregate the students and civilians to one area. An area you would already know the location of due to an Informant (draco or other present slytherin) and the Sirius extravaganza. knowing this you could then siege the castle with a small force so that they are not made aware to your plans. Once securing the rest of the castle minus the great hall you could simply magically lock the doors and exits to said hall in every way imaginable. Hell have every death eater cast a locking charm if you want, just secure it tighter than a goblins grip on your gold. After that wait for foolish Griffindorian hero to approach, upon his and hers arrival go through annoying pleasantries. After that inform the leader that the price of his tardiness and coward-ism is the death of every student, teacher, mother, father in the great hall. Tell him that you have sealed the hall irrevocably and cast fiendfire inside the room. Give him a choice toil uselessly against a dark lord for the sake of friends already dying, or attempt to save them from their fate. Now from this point forward there are several reactions that could occur, one: he ignores you and initiates combat despite the news in which case you are at an advantage as he is agonizing over his decision to abandon his friends, surrogate family, and mentors. Two: He begins battering the doors or walls his choice really, while cautiously watching you. But choose not to attack and the longer you wait the more inclined he will be to focus on getting the door open choose your own ideal time to strike. Third: and truthfully most likely he agonizes over the choice of whether to finally end the war and kill the murderer of his parents or saving everyone he values as close to him, your best choice would be to strike during this hesitation. and for merlins sake burn the goddamn bloody body when you're done. Seriously he survives one killing curse treat him like a bloody vampire or inferi. better yet avoid the killing curse altogether that didn't really work out the first few times now did it. It annoys me endlessly when obvious Griffindorians like Jk Rowling attempt to write the thoughts of the more cultured Slytherins, They can never understand the Depths of our Depravity.