Hugo

Hugo once was a mildly grumpy but carefree dragon with a mate and a home high in the cloudsong. One day, however, his mate disappeared. All that was left was a cryptic message describing some glacial ruins and a mention of redemption. When he arrived there she was gone. All that was left was a single gem - her parting gift. He knew then that she had left, like she had said she would so many times before.
Rather than turning and leaving, he entered the ruins. The labyrinthine interior of the maze of ice left him increasingly disoriented until he found himself utterly lost within the ice, a prisoner to its whims. He finally found a way out, but as he passed through the archway and into the frosty air, he realized too late what the runes on doorway had spelled out.
Youth.
The magic had turned him into a hatchling once again, and he found himself only able to fly short distances. His body was weaker, but he kept himself warm with the heat of the rage he felt at himself for falling prey to such an ancient curse. He's a very angry dragon, and most stay away from him, though Kokakku treats him like her child despite his insistence that he's an adult.
His ice magic is very weak, but he's able to produce small clouds of snow and ice that he can sit on until they disintegrate. He also likes to blow cold air and snow into the faces of dragons he dislikes. While he at first hated how his life has turned out, he grudgingly admits now that things aren't as bad as they could be - and he doesn't mind being treated like a hatchling now and then. He's found ways to work around his condition, and found a new mindset, even if outwardly he's still a massive grump. He assists Kokakku with tending to the hatchlings when he particularly misses his own.