Harry potter: I am the king of United Kingdom

Arthur stared at the Holy Sword Excalibur, its ethereal glow casting long shadows across the underground chamber. The blade radiated purity, a symbol of hope and unity. Yet, as he turned back to Atreus, he saw the weight of something darker in his brother's eyes.

"There's something else you need to know," Atreus said, his voice grave. He gestured toward the endless black water surrounding the platform. "Excalibur has a twin."

Arthur raised an eyebrow. "A twin?"

Atreus nodded. "The Ebony Blade. While Excalibur was forged as a beacon of light, the Ebony Blade was its dark counterpart. Merlin and Sir Percy crafted it from the Starstone meteorite, imbuing it with unparalleled power—but also with a terrible curse."

Arthur's gaze shifted to the water, a chill running down his spine. "What kind of curse?"

"The blade is nearly indestructible," Atreus began, his tone solemn. "It can cut through anything, deflect magic, and even absorb energy. It grants its wielder immortality—injuries can harm but not kill them—and binds to them so completely that it can be summoned across great distances. But…"

Arthur waited, the tension in the air growing thick.

Atreus took a step closer, lowering his voice. "The blade feeds on its wielder's darker impulses—violence, anger, the lust for blood. It grows stronger with every evil act committed in its name, and the more blood it sheds, the more it craves. If left unchecked, the wielder risks becoming something monstrous: a Bloodwraith, a being of immense power and malice."

Arthur shuddered. "And this… thing is here? Beneath us?"

Atreus gestured toward the black pool. "At the bottom of this water lies the creature that protects the Ebony Blade. To claim Excalibur, you must first descend into the depths and confront it. Only by defeating the guardian and resisting the Ebony Blade's temptation will you prove yourself worthy of wielding Excalibur."

Arthur hesitated, glancing at the serene light of Excalibur. "Why does the Ebony Blade even exist? Why create something so dangerous?"

"To maintain balance," Atreus replied. "Light cannot exist without darkness. Merlin believed the Ebony Blade could be a force for good in the right hands, but he underestimated the curse. Few have resisted its pull, and even fewer have used it without succumbing to its influence."

Arthur's mind raced as Atreus continued. "The Ebony Blade's power is vast. It can unleash devastating energy blasts, open doorways to other dimensions, and protect its wielder from psychic intrusion. It even resurrects its wielder if they are of King Arthur's bloodline, though at a great cost—the darkness grows stronger each time."

Arthur's breath caught. "It brings people back from the dead?"

"At a price," Atreus warned. "Each resurrection makes the wielder more susceptible to their inner darkness. The blade manipulates the soul, amplifying anger, hatred, and despair. It's said that the blade can even manifest black armor around its wielder, granting flight and near-invincibility."

Arthur's eyes narrowed. "And if I resist it? What happens then?"

Atreus smiled faintly. "If you resist the Ebony Blade's call, its power will not harm you. Only then will you be deemed worthy of Excalibur."

The enormity of the task loomed before Arthur. The weight of the Pendragon legacy, the lure of unimaginable power, and the threat of succumbing to darkness all pressed down on him.

"Why me?" Arthur asked, his voice barely above a whisper.

Atreus placed a hand on his shoulder. "Because you're the only one who can. The Pendragon bloodline has always carried the potential for greatness—and the burden of responsibility. This is your destiny, Arthur. But know this: the choice is always yours."

Arthur turned back to the pool, the still water seeming to ripple in anticipation. The faint glow of Excalibur remained steadfast, a beacon of hope amidst the shadows.

He clenched his fists, his resolve hardening. "Then I'll do it. I'll face whatever's down there, resist the Ebony Blade, and claim Excalibur."

Atreus nodded, stepping aside to give him a clear path. "Remember, Arthur: the test is not just of strength, but of will. Stay true to who you are, no matter what temptations arise."

Arthur stepped onto the edge of the platform, the abyss stretching out before him. The air grew colder, the weight of the moment settling in his chest. Taking a deep breath, he dived into the dark water, the light of Excalibur fading as he descended into the depths.

The trial had begun.