Kyran had to go to the Crespuscule Auction House for a few reasons. And one of the big reasons was currently being fulfilled— a chance to enter the Crepuscule Treasure Vault.
Such a reason was not unexpected because most clans in the Higher Realm would also like to have a chance to enter their vault. However, the reason those clans wanted to enter the vault was very different from Kyran's. Those clans wished to enter and find a way to steal their treasures, but Kyran only wanted to take a look at them. After all, that was all he needed to recreate them— at least, that was the case with rare materials and items, as well as treasures created from Array.