Harry tugs on the chains binding him and is dismayed to find that they were locked down tightly. He felt that he could still use his magic, but the chains felt oddly resistant to his attempts to unlock them.
"Oh, don't mind them. The chains are merely to set the atmosphere. You are going to die in a horrific way, after all"
...
"I do have a question for you... How are you able to use magic so easily with this?" the Necromancer asks while holding up a ring for Harry to see. He quickly recognises it, a blank gold ring that he'd been practising demonic runes on, they weren't active and actually half-finished, not magical in any way... Was the Necromancer mistaking it as a focus?
"You're going to turn me into an undead... Will I keep my mind or...? Because I'm not that against it, to be honest." Harry offers, wanting to keep the Necromancer distracted so he could come up with a plan...
"You are smarter than the people of my time, boy. Immortality is always worth it, no matter the costs. To live for eternity, albeit in a mindless state, is preferable in my eyes to mortality. Sadly, you will not become one of my many servants, you are simply too valuable to go to waste on such projects... Instead, I will take you into myself, add you to my power.. We will be one, but only I will remain.
I must thank you though, that snake of yours is a creature I have not added to my collection yet... Its skeleton and overall physiology are well suited to becoming an undead... I wonder if I'll be able to make its eyes work after they begin to decay...?" the Necromancer mutters the last part to himself.
"You have an amazing library, you must have spent many decades on that collection..." Harry probes, feeling the book he'd hidden still held by the band of his trousers.
"Mmm, yes, I suspect it is the most valuable collection of knowledge left in this world. I wish I was able to compare it to the Library of Alexandria before those scum burnt it." he shakes his head sombrely. Any last words, boy? I will do my best to inscribe them onto your family's bones once my plans come to fruition."
"Yeah, my parents are already dead." he retorts, mustering his magic and levitating the Necromancer's book in front of himself. His arms and hands were bound, so the lack of movement made it difficult, but he'd trained enough to manage at least this. "Also, this book isn't as interesting as you make it out to be... Maybe it'd be better burned, like Alexandria." he says, conjuring a flame beneath it, just close enough to warm and threaten it but not yet burn.
The Necromancer freezes, the glowing blue lights in his eye sockets flaring with power and hostility. "You dare!?"
"I do dare! Wanna take my bluff!?"
"Hehehhehahahaha! Foolish boy! Read the title of the book you stole, and recognise your doom!"
...
Harry turns it, "Journal of the Great Amarant Zorander..."
"Go ahead, burn it. I will just write another! Hhahahaha!" the Lich cackles madly in amusement.
Harry growls, doing just that, burning the journal to cinders to spite the Necromancer, who instantly stops laughing in response. "What's wrong? Upset? Well isn't that too bad-Ah!" he's interrupted from his mocking as the chair he was sitting in drops, causing him to fall right into the pool of thick blood.
"AAARGH!" He screams out, surprised at the feeling of the blood around him. It wasn't cold like he'd assumed, but hot, boiling hot! Not only that, but it felt caustic to his skin, like acid!
Instantly, any flesh that makes contact with it turns grey and starts wrinkling, as if the water in his body were being sucked out through his skin. He grits his teeth but isn't able to stop himself from screaming in agony.
He could feel it, not just physically, but magically too. It wasn't just blood, it was concentrated enough to make it almost sludge-like, and was filled to the brim with death, hate, malice, and regrets of the Necromancer's past victims... That wasn't all... It was filled to the brim with magic... Magic that felt connected to the Necromancer... Was this acting as a substitute to his core!?
He had no time to contemplate that, right now he needed to stop himself from shrivelling up and becoming another magic battery for that bastard. He flexes his scorched hands and pumps as much of his remaining magic into casting the Blood Leech spell that Kali had taught him.
The Necromancer wasn't able to see or sense the crimson snakes that form within the pool of blood, but was certainly able to sense it when blood started to pump through them and back into Harry.
"UUUGGaaaAAggh!" Harry exclaims as he feels pure, unadulterated power flow through him. The blood he was absorbing was nothing like anything he'd experienced before. He felt like he was all-powerful, and the only thing that came close was his first ritual where he'd bartered Voldemort's soul to a Demon God for power.
"W-WHAT ARE YOU DOING BOY!? STOP THAT THIS INSTANCE OR SUFFER THE CONSEQUENCES!" the Necromancer roars as he floats from his throne, staff in hand.
The next thing Harry felt was sheer malice for the Necromancer. All of his past victim's hostility towards the sick creature screamed out in his mind for retribution, for revenge!
Harry might have a stronger will than most people his age, as well as a basic mastery of occlumency, but that what nowhere enough to separate his thoughts from those now in his head. "AAARRRRGGGGGGHHHH! XIMIKI! Ⲙⲏⲧ! ΠΈΘΑΝΕ! DIE! DIE! DIE!" he babbles in multiple random languages, his mouth moving on its own as its shouts out vulgarities and curses.
The chair and chains binding him explode into fine powder as he's left floating in the pool of blood, a crimson glow covering him as he absorbs more and more blood. His skin heals, becomes scorched again, and heals once more.
His magic was constantly getting sucked out by the pool, but he was just absorbing it back into himself via his snakes. "AAGGH! DIE!" Harry screams out as a tangible wave of magic explodes outwards from him, knocking the surprised Necromancer from the air as his conjured ward completely fails to protect him.