In a world of misty mountains and scorching volcanoes, where starlight was sown into the night by the dance of drakes and the whispers of the winds were the songs of dragons, lived Kys, the young Thunder-dragon. Kys was still small, smaller than his siblings, smaller than the majesty his species was known for. He dreamt of growing big and strong like his elder kin.

Kys wasn't alone in his adventures. Loyal Major and playful Mya, his trusty dog companions, were always by his side. Major was a wise old soul with a heart as brave as a dragon's fire, and Mya was a bundle of joy and mischief, sharp as a spark and swift as a shadow. Kys, Major, and Mya were an inseparable trio, each integral to the other.

"I'll grow, you'll see," Kys would often declare, his scales shimmering with determination against the morning sun. Determined, yes, but the young Thunder-dragon had a lot to learn about patience.

One fine day, Kys, Major, and Mya embarked on a challenge, spurred on by a tale of an ancient dragon who had grown infinitely powerful by consuming the heart of a star.

Unbeknownst to them, the heart of a star was no ordinary star, but a special droplet of radiant moonlight, unseen and untouched by any mortal or dragon. It was a challenging task, filled with perils and tests of courage, and Kys was eager to undertake it.

"I want to grow stronger than any dragon!" Kys declared, his voice echoing in the empty cavern. But Major, the wise old dog, questioned, "Is strength only about being the biggest and the strongest, Kys?"

In his hurry to prove his worth, Kys ignored his friend's wise words. The journey was challenging, filled with problems that required not strength, but wisdom. With every trial they faced, Major and Mya always found a way around, and each time Kys would marvel, learning the importance of quick thinking and teamwork.

Their journey led them through the Valley of Whispers and across the Ocean of Obsidian, right into the belly of the Midnight Mountain where the heart of a star was said to reside.

It was not size or strength that helped Kys snatch the star's heart, but his quick wit and the combined teamwork of Major and Mya. And when they finally held the radiant heart, it did not radiate strength, as Kys had imagined, but wisdom and knowledge.

The heart shared the ancient knowledge of the universe with Kys, tales of dragons who were strong not by size, but by their wisdom, their courage, and their kind hearts. With this realization, Kys understood the true meaning of strength and growth.

Back in his world, Kys felt a change. He had not grown in size, but his heart felt larger, his mind broader. His dream had shifted from growing physically to growing metaphorically. "Real strength," he told his kin, "lies not in our size, but in wisdom and kindness."

His siblings listened in awe as Kys shared his newfound wisdom, and they understood the true essence of a dragon's strength. Kys, the tiny Thunder-dragon, may not have been the biggest of them all, but he became the wisest, the kindest, and thus, the strongest.

In the end, everyone celebrated Kys's growth and wisdom. Major and Mya wagged their tails happily, knowing their friend had learnt a valuable lesson. As the moon shone brightly on the world of dragons, Kys realized the importance of thinking before acting. It was a happy ending, indeed, for the tiny Thunder-dragon who dreamt of strength and grew in ways he'd never expected.