Scenario 3:
Frank is initially ignored, what with Diagon alley being accustomed to people like Hagrid walking through. Taking advantage of this, he proceeds to find the best firing angle. With everyone funnelled into the alley, it's going to be a massacer.
Upon finding a good spot, Frank lifts his arm with the End Boss Gun and says, "Ride's over muties, time to die." He unleashes hot plasma in a rapid flurry that vaporizes the otherwise unarmored wizards and other miscellaneous critters. Others rush outside to see what's going on and he adjusts his firing arch to encompass the doorways.
Finally out of ammo and an alley full of green goo corpses, Frank drops the gun and pulls out the End Boss Knife. Some wizards build the courage to step outside, wands drawn. Now in juggernaut mode, Frank is running down the alley with his seven foot long blade. The first wizard tries to say the words to a spell but studders at the sight and gets cleaved.
The leaders of the wizard community finally arrive via a multitude of methods and are shocked at the mess left in Frank's wake. Frank has escaped into daigon alley, ripping apart dark wizards with seeming ease in the ominous fog and tight corners. He'll be back...