Itachi Uchiha, a mysterious figure from a distant world, found himself in the wizarding world. He was invited to Hogwarts School of Witchcraft and Wizardry to understand the magic of this world and teach them of his own mystical powers.

Luna Lovegood, a student at Hogwarts, was mesmerized by Itachi from the moment she saw him. She was captivated by his enigmatic aura and the unfathomable depths of his red eyes.

During dinner in the Great Hall, an unwelcome guest arrived. Voldemort, the dark lord, had come to infiltrate Hogwarts and spread fear among its inhabitants.

However, Itachi remained unfazed by Voldemort’s presence. "Who is he?" He asked calmly, not showing any signs of fear or surprise as others did.

Harry Potter, another student at Hogwarts, was the one to answer. "That's the Dark Lord," he said, his face pale but determined.

Voldemort, keen on showcasing his power, cast the Avada Kedavra, the death spell, on Itachi. However, to his disbelief, the spell did not reach Itachi.

With a swift and effortless motion, Itachi grabbed the spell and destroyed it with his bare hand. The act left everyone in the hall in utter disbelief.

He then elucidated on the nature of his power, comparing it to the paradox of Achilles and the turtle, prompting bewilderment amongst the students and staff.

The next instant, Itachi was right in front of Voldemort. His grip crushed Voldemort’s wand-wielding hands, forcing the Dark Lord to his knees.

Itachi then summoned the Totsuka Blade, a spectral weapon known for its sealing abilities, and effectively sealed Voldemort, effectively removing the imminent danger.

Albus Dumbledore, the headmaster of Hogwarts, approached Itachi. "Itachi, what is this ‘Limitless’?" He questioned the peculiar man in front of him.

Itachi explained to Dumbledore that his ability allows him to manipulate space at will, inhibiting things from reaching him, demonstrating this by allowing Dumbledore to attempt touching his hand.

Dumbledore tried, but he could not touch him, much to his astonishment. The concept of Itachi’s power was beyond even his grasp.

Harry, along with the other students, were equally amazed. They had never witnessed such a strange and powerful ability.

Itachi explained his power further, using a mathematical analogy, explaining how he creates a convergence of infinite series in space, to Dumbledore's interest.

Luna, meanwhile, was in awe of Itachi's power. She found herself developing a deep respect for him and felt an inexplicable connection.

Time passed, and Itachi continued to coexist with the inhabitants of Hogwarts. He was a mystery they all wanted to unravel, yet remained an enigma.

Luna, in particular, found Itachi to be a constant source of fascination. She tried to understand his world and the power that he held.

Dumbledore, with his vast magical knowledge, was the only one who began to understand the concepts Itachi explained about his powers and the world he came from.

Harry, who had initially been wary of Itachi, began to view him as an ally. He acknowledged the power Itachi held could potentially help them in their fight against dark forces.

As the term neared its end, Luna approached Itachi. "I'd like to understand more about you and your world, Itachi," she said, her eyes earnest and kind.

Itachi paused, looking at Luna. He then nodded, a small smile playing on his lips. He was willing to share his world with Luna, as she desired.

Dumbledore, hearing of this, arranged for Luna to learn from Itachi. He knew that their shared curiosity and unique perspectives would foster a productive relationship.

Luna spent most of her time with Itachi learning about his techniques and his world. She found that the more she learned, the more she admired him.

Itachi, in turn, was intrigued by Luna's understanding and constant thirst for knowledge. He saw in her a kindred spirit, a connection he hadn't expected.

And so, Itachi Uchiha, with his limitless power, left an indelible mark on the wizarding world, becoming an unexpected ally and a bearer of hope.

His story became a legend within Hogwarts, often recounted by Luna and Harry to new students. His powers, his wisdom, his enigma was a tale never forgotten.

Luna Lovegood, under Itachi's tutelage, grew to become a bridge between the wizarding world and Itachi's world, fostering an understanding between two vastly different realms.

Dumbledore often remarked that Itachi's arrival was an unexpected gift. His power had challenged their understanding, and his wisdom had imparted valuable teachings.

Even after his departure, Itachi's legacy lingered on in Hogwarts. His teachings continued to flourish within the school, his power forever a part of their lore.

Harry and Luna, with an understanding of Itachi's power, stood stronger against the dark forces. Indeed, Itachi Uchiha was the limitless master, and his influence was unforgettable.