In a fantasy world made up of different mythical races, dragons age differently from the rest of the world, meaning, that their soulmates that don't live as long as them most of the time

An example would be when a thousand years ago, Katsuki Bakugou, fell in love with a human. They were happy, loved eachother wholeheartedly, until his beloved human mate passed. Katsuki went back to his old ways, and focused on ruling his kingdom

On a faithful day whilst attending a party with other mythical creatures, his instincts instantly flaring, inner dragon stirring alive as a newcomer walked in, howling 'MATE'S BACK- MATE'S RETURNED!'

After a thousand years of waiting- His soulmate had been reincarnated and reborn