"The Elder Wand might be yours, but you don't have it, I do. We duel on skill alone. Unfortunately for you, I am still the greatest wizard alive! And after I have killed you, I will finally have the Wand's allegiance."
This was it, thought Severus. The moment of bravery. Head on it was, then. No trickery, no element of surprise. Severus lifted his chin high and looked Voldemort straight in the eye.
"We shall see, won't we? Unlike you, I'm not alone," he said and smirked as he glanced at Minerva. She did not fail him. A typically Gryffindor, she stepped forward, her wand ready.
The enchanted sky above them was suddenly ablaze as the edge of dazzling sun appeared over the sill of the nearest window. The light hit their faces and rendered everything around them to a flaming blur. Severus heard Voldemort's high voice shriek. He ducked just in time while throwing a curse at his nemesis' silhouette, knowing that it would probably miss him. And so the final stage of the battle began.
Snape lashed at Voldemort with all his might. Curses thundered out of his wand, but Voldemort twirled around and deflected them skilfully, sending his own cursed at Snape. He couldn't move as fast as Voldemort because of his injured leg, but somehow he didn't need to. Voldemort spells seemed to have little effect upon him anyway, and with Minerva and Molly's help, not a single one hit him. Even Potter proved useful from time to time. Though his attempts at disarming Voldemort were futile, Severus had to admit that the boy's Shield Charms proved to be extremely strong.
Others joined in the fight. Order members, Slughorn, Flitwick, Aberforth, and others encircled the combatants, their wands raised. Only a few could fully engage in combat. They needed a clear view of Voldemort, and they certainly didn't want to hurt each other while aiming at him. Only two of them, namely Flitwick and Kingsley, joined in to fight Voldemort in the inner ring. Severus could soon see why Flitwick had been a duelling champion in his youth. The tiny wizard was the only one who managed to get very close to hitting Voldemort with a Blasting Curse. Unfortunately, the curse only tore apart the hem of Voldemort's robes. Voldemort didn't even notice it since he was busy firing curses in every direction, even at the crowd leaning against the walls of the Great Hall. Luckily the outer ring, namely the rest of the Order along with Slughorn and Aberforth, stayed vigilant for such occurrences.
The fight seemed to lead nowhere for what must have been several minutes. Voldemort's six opponents all wove and ducked around him, but were still unable to finish him. Neither could Voldemort finish any of them. He seemed particularly keen in finishing Severus first, clearly wanting to gain the Elder Wand's allegiance, but he couldn't even get a proper aim at him. Due to multiple attackers, he couldn't focus solely on Severus. He roared in frustration. Severus instinctively knew then what Voldemort was about to do. He cast a Protective Charm at the same time as a loud bang reverberated all over the castle and shook it to the foundations, sending Voldemort's opponents flying backwards helplessly. Severus' hair was swept back by the powerful blast, but nevertheless, he was still standing alongside Potter. The three wizards stared at each other with cold hatred.
"You are a coward, Severus Snape!" Voldemort hissed mockingly. Severus' face hardened. "Hiding behind your little friends! You're just like Potter!" he spat in disgust. "Unlike you, I do not require help!" the dark wizard shrieked. "You don't have the guts to stand up to me all by yourself! What disgusting sneaky little cowards you are, the both of you!"
Severus ignored his taunting, and so did Harry. He knew Voldemort was getting desperate and he couldn't care less what that scum thought of him. He sneered and resorted to the same tactics.
"How does it feel, Voldemort? How does it feel knowing that the man you thought to be your most devoted servant was spying on you the whole time?" Severus hissed and relished in his words. "How does it feel to be all alone?"
"There can be only one at the top!" Voldemort roared madly.
Severus had had enough, and so he lifted his wand and without warning shot his own spell again, his Sectumsempra, at the Dark Lord. The latter deflected it, his face contorted with rage, but strangely, he didn't attack back. He wavered, glancing at the wand in his hand.
"What are you waiting for? Are you afraid the Elder Wand will not obey you when you order it to kill its true master?" Severus said provokingly.
Voldemort did not retort. He attacked instead like an irritated venomous viper.
The two wizards engaged in deadly combat. The air was hot with magic. Sparks flew in every direction, the smell of melted metal accompanying them. They were fighting to kill. Voldemort, with the wand that would not fully obey him, and Severus, with the injury to his leg, they were equal opponents. Everybody else retreated against the stone walls, observing the fight with fascinated horror.
One of Voldemort's spells missed Severus and hit the upper corner of one of the windows behind him. Severus didn't see it, but he could hear that the structure collapsed upon the spectators. He didn't dare to turn around. Someone must have been hurt judging by the screams. Voldemort threw his head back in a vile hysterical cackle.
Severus grabbed the opportunity the moment it presented itself. But Voldemort's reflexes were fast and Severus' curse only grazed him. A gash appeared on Voldemort's snake-like face. A small streak of dark blood poured down his cheek. Voldemort touched it and brought his fingers back in the line of sight. He was shocked.
"You will pay for this!" Voldemort roared in fury, but Severus didn't let him linger on that feeling. He fired curse after curse at him and desperately hoped one might eventually reach its destination. None did. Voldemort laughed mockingly at Severus' futile attempts. Severus got a very nasty feeling, that while he was throwing all he had at the dark wizard, the latter still hadn't yet used his skills to the full potential.
"You can't beat me, Snape! I am more powerful and I shall have the last word!" Voldemort exclaimed madly and waved his wand wildly.
The furious onslaught forced Severus to stagger backwards. He tried to hold his stance but slowly he was becoming tired. His leg was throbbing with pain and he was becoming drowsy due to the blood loss. He wasn't sure how long he was going to last. Then again Voldemort was also slowly becoming drained. Severus was suspecting that it cost him a great deal of energy to control the Elder Wand in combat against its true master. Surely enough Voldemort ceased the attack, his chest moving up and down with every ragged breath.
"Enough with the games!" he hissed slightly short-winded. "Let's see if Potter's little friends are really protected from me as he claims."
Something besides the sun was starting to glow bright orange, and it was coming from within. Severus realized with horror that Voldemort had cast Fiendfyre in the middle of the Great Hall. People screamed and ran in every direction as enormous fiery serpents coiled and uncoiled around them with a roaring noise.
Snape lifted his wand high up, trying to tame the fiery beast. Seeing his attempt, Voldemort laughed mirthlessly. He was silenced as soon as Severus successfully dispelled the scorching flames and prevented them to feed upon the wooden tables and benches left in the hall.
"You think you can stop me, traitor? You are no match to Lord Voldemort!" the dark wizard screeched.
"You're forgetting one thing!" Severus yelled. "I am the Headmaster of Hogwarts. You're in my territory, Voldemort," he yelled and knitted his brows with concentration. He felt confident as he made a wide gesture with his wand, urging Hogwarts to fight back. Perhaps he couldn't tame the cursed flames, but he had an idea of how he could limit their reach.
The ground started to shake, and Voldemort's wild grin was quickly replaced by a panicked expression as something dark and tall started to rise around him. A stone wall was erected in the middle of the Great Hall, encircling Voldemort and his cursed fiery snakes, and enabling people to run to the safety of the Entrance Hall. Some stayed behind, mostly Order members, who wanted either to witness the combat or aid in it.
"Careful, I think it's trying to escape," Minerva warned him as she saw how Fiendfyre serpents were trying to climb over the encircling walls.
"Allow me," piped Flitwick and started to chant an incantation, waving his wand delicately. Flitwick pointed it at one of the windows, and soon Severus realized why. A stream started to surge upwards from the Great Lake to the castle; a large watery serpent coming to aid them in the fight against its fiery cousin.
The fiery monsters climbed over the stone walls but were met by their watery opponent, which was controlled by Flitwick. The two creatures attacked each other ruthlessly. Severus tried to tame Fiendfyre again, but it was still too strong to handle.
Flitwick sent his complex Water Charm on top of it. The Water Serpent splashed over the coiling flames and combined with Severus' attempts at dispelling the blaze, it finally extinguished the Fiendfyre with a great hiss. People who remained in the Hall, despite the dangerous fiery beast, cheered loudly as it was destroyed. The air was full of smoke, dust and vapour. Voldemort was nowhere to be seen.
Severus became nervous and swiftly brought down the stone barriers he conjured. He strained his eyes, trying to distinguish the silhouette of the dark wizard among the clouds of smoke. He approached cautiously, his back safely turned against the wall, his wand ready. Perhaps, if they were lucky, Lord Voldemort had been killed by his own curse...
Suddenly a flash of green light hit him and he knew no more.