You can exchange your unused items with other items among these 4 exchangeable categories,
which are equipments, rides, guardian fairies, and costumes.

For rides, guardian fairies, and costumes, You can exchange unused shards for other shards.
For equipments, you can exchange your Mythical or higher grade equipment for different
Mythical equipment of the same part.

Mythical exchange requires Ancient Dragon Scales, Upgrade Stones, and Gold.
You can even obtain Mythical+ equipment at a small chance.

While exchanging Mythical+ equipment, you are guaranteed to acquire Mythical+ equipment in return.
However, required materials may vary from the material required for Mythical equipment exchange.

The amount of required shards and exchange cost depend on the quality of the item you want to exchange for.