"As our resident Potion Master, Professor Snape has fallen ill, I will be the one to teach you until he recovers." Dumbledore humbly says at the front of the class, and Harry can't help but inwardly snicker at the celebratory expressions on the Gryffindors and the mournful ones on his own Housemates.
Though, since the absence of Snape meant they were getting taught by THE headmaster, the more ambitious and less emphatic of the lot didn't care much.
The twinkle in the man's eye as he met Harry's did put him on edge, but he quickly moved on and began instructing the class on the brewing of 'Cleansing Potions', something that was scheduled for second years...
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The Great Hall was abuzz, as though the place was decorated almost entirely in green, even the Gryffindors were getting in on the midday celebration—Saint Patrick's Day.
No drinking was allowed, but that hasn't stopped the school faculty from charming the pumpkin juice to turn the skin of those who imbibed it green. The twin pranksters had seen this as a challenge of course and now Professor Flitwick was sitting at his table in a leprechaun uniform.
Not that this mattered to Harry, as he wasn't even in the school during this...
Harry had snuck out of the castle in the morning with Nanthisk and Kali to take advantage of this particular day. While to most Saint Patrick's Day was one of celebration and levity, to other now-extinct groups, it was one of oppression and genocide.
Saint Patrick's Day signalled the dawn and beginning of Christianity on the Isles, which just so happened to also mean the persecution and exploitation of those who worshipped pagan gods and traditions.
This of course meant that pagan-related magics and rituals should be far weaker on this day... But Harry was actually counting on this... With the Holy Grail in his bad, he and his familiars made their way to the Hill of Tara, where the Stone of Destiny had grown ancient.
It was perhaps one of the most important sights in all of Ireland, for both its history and ancient forgotten traditions...
"Are you going to tell me why we're here, master?"
"Did you bring what I asked?"
She nods, "I have one seven-leaf clover, and a box full of lesser ones. I have the hands and tongues, a pitcher filled with pedophilic priest blood, and some unhatched snake eggs."
"We're a bit late, so I'll explain after we do it." he says as they stop before the Stone of Destiny. There, he lays the Holy Grail at the foot of the stone and glances up at the high-noon sun. "Síocháin do sinsear na n-oileán, ríthe na mblianta atá caite." he chants as he fills the grail with the priest blood, "Tugaim bronntanais chugat, díoltas i gcoinne na n-ionróirí bréagacha."
He gathers the many clovers and surrounds the cup with it, like kindling for a campfire. "Chríochnaigh na haspail demonic do thailte agus do dhaoine, ní iarraim ort ach cabhrú liom ar a seal." he places the snake eggs into the goblet, causing blood to overflow and spatter the clover leaves.
"Tugaim chugat a ndéantán is naofa. Déanfaimid ár gcuid féin é agus fliuchfaimid é lena gcuid fola, casfaimid é i gcoinne a máistrí!" he shouts, igniting the clovers with a small demonic fire and causing a green fireball to encompass the goblet.
The fire doesn't last long, burning out in a matter of seconds and revealing a slightly scorched grail. In its cup the blood was gone, replaced with many bright green baby snakes. He retrieves the hands and tongues of the devout Christians and cuts small pieces from them before feeding the creatures, commanding them to eat.
They ate until they couldn't, then more. He force-fed them, and through this process, only one was left alive. Its green scales peeled off to reveal the black flesh underneath, its stomach bulging with Christian flesh.
As if commanded to, the snake slithered out of the cup and wrapped itself around the base... Before finally going still, locking up as if under the effect of rigor mortis.
Harry lets out a long sigh and takes the grail, holding it up in the sun... Only allowing a smile when the snake's bodies petrify, turning ashen around the scorched grail.
"Is it done?" Kali questions.
He nods, "For now. We'll need to come back and do the same five more times. Six times is close enough to the number of the beast to work, even if it isn't perfect."
The ritual was essentially a giant 'fuck you' to Saint Patrick and Christianity as a whole. They'd used the body parts of devout followers and a heretical one, burned the symbol of Saint Patrick, clovers. And finally, he'd hatched snakes in a sacred artifact... Since the Saint was supposedly the one who banished snakes from Ireland, birthing new ones here and now was the final nail in the coffin.
Of course, the Holy Grail was too powerful to succumb so easily, so it'd take another five years to fully corrupt it. Hopefully then he'd be able to make full use of its abilities, since he refused to give any credence to God or whatever being he purported to be.
"Well done master... I think this may be the best ritual you've ever devised, aside from the one that brought me to you." she smiles
Facetious or not, she wasn't wrong. The fact he'd been able to corrupt the grail to such a degree with a single ritual was impressive... He runs a finger over the blackened gold of the cup, taking in the smell of rotting blood now emitting from it. "Are you able to hold it?" he questions, knowing the artifact was a like a magnet for her, pushing her away with both pain and force.
Kali easily takes it up, looking smug at the vessel, "Hmph, a gift to humanity no longer. Now, we must hurry you back to school before they notice your absence, Master."