[System Message:  Wraith Form of Voldemort. Extreme caution advised. Known for his malevolence and strong dark magic. Currently in a weakened state but highly dangerous.]

Without a moment's hesitation, Harry whispered, "Lumos Maxima," but not in the common tongue. Instead, he used the Unicorn language, infusing the spell with a purity and a serene aura that he had developed through his experiments in the Virtual Room. The light that burst forth was not just bright; it was ethereal, shimmering with a serene glow that seemed to calm the night itself.

"Sadly, I don't know the Patronus Charm yet," Harry thought to himself, a bit of regret lacing his silent admission. The light, however, did its job, causing the wraith-like shadow to recoil as if struck by a physical force. The Unicorns, sensing the change, seemed to rally, their own innate magic responding to the purity emanating from Harry's spell.

Gathering behind Harry, the Unicorns infused their magic into his, creating a bond that transcended visibility. Despite the cloak rendering him unseen to the eye, the Unicorns felt a kinship in the magic emanating from him. The forest, bathed in the ethereal glow of his spell, became a stage for a silent but powerful confrontation between light and darkness.

The Unicorns, majestic and serene, formed a semi-circle around Harry. Their horns, shimmering with a pure light, added strength to the Lumos Maxima spell. The wraith-like shadow, now clearly on the defensive, hissed and writhed as if in agony, its form flickering and unstable under the assault of pure light.

Harry, though invisible, stood at the center of this unlikely alliance, a testament to the unity that could be forged between human and magical creatures against a common foe. The air around them seemed to throb with power, a silent symphony of light against darkness, purity against corruption.

Nigel, witnessing this through Harry's eyes, couldn't resist commenting, "Ah, the power of teamwork, eh, Master Harry? It seems even cursed shadows can't stand up to a bit of unicorn camaraderie. Makes you wonder why we don't host more magical creature mixers."

The shadow, realizing the futility of its assault, began to retreat, melting into the deeper shadows of the forest from whence it came. The Unicorns, sensing the victory, let out a series of gentle, melodic sounds that filled the night air with a sense of peace and triumph.

Harry, lowering his wand, whispered a heartfelt, "Thank you," to the Unicorns, their innate kindness and strength having turned the tide of the confrontation. As the light from his spell faded, the forest returned to its nocturnal calm, the only evidence of the encounter the lingering sense of magic in the air.

After ensuring the area was clear, Harry carefully draped the Invisibility Cloak over his arm and approached the Unicorns. They gracefully bowed their heads in a gesture of respect and gratitude. Harry, feeling a bit awkward with such formalities, spoke to them in their own language, "There's no need for bowing."

One Unicorn, with a coat shimmering like moonlight on snow, stepped forward and gently nuzzled Harry's hand. "Young Wizard, you have aided our kin and spoken our tongue," she said, her voice a melodic harmony that resonated with the magic of the forest.

Harry, touched by the gesture, responded, "I did what anyone would have done in my place. Your presence in the forest brings balance and peace; protecting that is important."

Nigel, observing the exchange, quipped, "And here I thought you preferred the company of books and potions. Seems you're quite the unicorn whisperer, Harry."

Harry smiled at Nigel's remark but chose not to respond directly. Instead, he focused on the Unicorns, their serene beauty a stark contrast to the darkness they had faced together. "Is there anything else I can do for you?" Harry asked, genuinely concerned for their wellbeing.

The lead Unicorn shook her head, her mane catching the moonlight in a cascade of silver. "Your heart is pure, and your actions brave. We owe you a debt of gratitude. The forest is safer tonight because of you."

As Harry bid the Unicorns goodbye, cautioning them to be careful, he once again enveloped himself in the Invisibility Cloak's protective embrace. The forest, now silent save for the soft rustle of leaves and the distant calls of nocturnal creatures, seemed to hold its breath. Suddenly, the sound of hooves broke the silence, and Harry found himself surrounded by centaurs, their imposing figures barely visible in the moonlight.

One centaur, who stood slightly ahead of the others, fixed his gaze on space where Harry stood. Although Harry was hidden under the cloak, it seemed as if the centaur's eyes pierced right through it. "The heavens are particularly clear tonight," the centaur began, his voice resonant and deep, "Venus shines brightly, heralding an evening of change. Had it not been for your intervention, young wizard, the dark shadow that sought to disrupt the harmony of the forest might have succeeded. Your actions have averted a calamity this night."

Harry, taken aback by the centaur's insight, remained silent, marveling at the mystical connection between the centaurs and the cosmos.

Nigel, observing silently up until now, couldn't resist commenting, "Ah, centaurs and their celestial observations. Always a bit on the nose, aren't they? I suppose next they'll be telling us that Mercury in retrograde is to blame for the castle's plumbing issues."

Harry stifled a laugh, careful not to reveal his presence. He was mortified Nigel's attempt to lighten the mood, even in such a mystical setting.

The centaur continued, seemingly aware of Harry's presence despite the cloak. "The stars have much to say to those who listen. Your fate, young wizard, is intertwined with the movements of the celestial bodies. Tonight, Venus acts as your guardian, casting a benevolent light upon your path."

Harry, fascinated by the centaur's words, couldn't help but wonder about the connection between his actions and the broader movements of the universe.

Nigel, ever the skeptic, chimed in, "Well, if Venus is on our side, perhaps we should send it a thank-you note. Do you think she prefers parchment or email?"

The centaur, seemingly concluding his observations, gave a final nod in Harry's direction. "Be wary, young wizard. The forest is full of secrets and dangers. Your heart may be pure, but the path you walk is fraught with shadows. Tread carefully."

As the centaurs turned and disappeared into the depths of the Forbidden Forest, Harry felt a mix of awe and curiosity. The encounter had been brief, but the centaur's words echoed in his mind, a cryptic message wrapped in the mystique of astrology.

Nigel's voice broke through Harry's contemplations, "Well, that was rather cryptic, even for centaurs. I suppose we should be thankful Venus was in a good mood tonight. Makes me wonder what they would have said if Mars was in the lead."

Harry smiled at Nigel's commentary. "I guess we'll never know, Nigel. But I'm grateful for the centaur's insights, cryptic as they may be."

Harry then turned the conversation towards a topic that had been lingering in his mind. "Nigel, you seem quite sullen about Centaurs. You've never shown displeasure towards magic itself, but you're notably guarded against divination." Harry's curiosity was piqued; Nigel's stance on this specific branch of magic was intriguing.

Nigel snorted, his tone laced with his usual sarcasm. "Oh, it's not 'Divination Magic' per se," he emphasized mockingly. "It's that it operates beyond the realm of magic's control. It irks me."

Harry, still puzzled, pressed on. "Not magic? Then what is it?" His confusion was evident, trying to grasp Nigel's nuanced viewpoint.

Nigel, sensing Harry's confusion, decided it was best to steer the conversation away from the murky waters of divination and its uncertainties. "Let's just say, it's late for talks about the future," he remarked, deflecting with his typical sarcastic flair. "Better to focus on the here and now, where we can actually make a difference."

Returning to his room secretly, Harry slid under the covers, exhaustion quickly pulling him into sleep. His thoughts swirled with the day's events, but they were no match for the physical toll his body had endured. It had indeed been a long day, filled with both peril and discovery, and his body demanded rest.