"The Heartwood Citadel"
Lyra stood before the ancient Heartwood Citadel, its massive gates carved with symbols of Aethoria's creation. The air vibrated with power, and the trees seemed to lean in, as if listening. She pushed open the gates and stepped into the grand hall.
A hooded figure awaited her – the Guardian of the Heartwood. "To claim the final key," it said, its voice like rustling leaves, "you must face your heart's desire."
A vision unfolded: Lyra found herself in a lush garden, surrounded by loved ones she'd lost – her parents, friends, Elara. They smiled, reaching out, offering her a life of peace and belonging.
But Lyra saw the catch – this was a dream, a prison. The Moonstone's power stirred within her, urging her to break free.
"I choose Aethoria," she said, her voice firm. The vision shattered, revealing the Guardian.
"Your heart is true," it said, offering the final Celestial Key. "The shadows close in. Unlock the Moonstone's full power – but remember, with great power comes great cost."
Lyra took the key, feeling Aethoria's fate balance on her shoulders. The Moonstone pulsed, ready to unleash its might. But at what price?