The chains play an important role in Pandora's Tower. Not only do twelve massive chains (large enough for Aeron to run along) keep the Thirteen Towers suspended above The Scar, preventing The Scar from engulfing the world, but a number of chains in each Tower also lock the door to the Master's chamber, preventing the monstrosity from breaking free and attacking the people of Elyria, or any other kingdom. These chains must be destroyed by Aeron to access the Master's room and defeat it.
The number of chains in each Tower will be shown at the start of the Tower when a cutscene shows you the door to the Master's chamber, as well as by looking at how many chains the statue of the god/goddess is holding. However, as the chains are destroyed, the chains will no longer appear in the god/goddess' hands. The chains can also be seen in the Tower, which allows you to follow them once you find them until you find the Chain Room where they are rooted. By destroying the base of the chain in the Chain Room, the chain itself will be entirely destroyed.
The number of chains in each Tower are as follows: