Half Dragon Square Shield

These two halves of the Dragon Square Shield are used to form the said item.

To obtain such a shield, you must first purchase the right half for a hefty 750,000 coins from the Legends' Guild store. Then, you must obtain the left half as an extremely rare drop from various monsters including Shadow Warriors in the Legends' Guild dungeon. Once you have both halves, go to an anvil with level 60 smithing and combine the two, creating the legendary Dragon Square Shield.