Key of the Tower

Key of the Tower (official name unknown), is an important "key" to opens the sealed door on the 134th Floor. This door was locked by Zahard to prevent everyone to enter the 135th Floor and beyond.

History
On the day Zahard declared himself the King of the Tower he decided to stop climbing, thus hiding the key that would open the door leading to the higher Floors so that no one could go beyond the 134th Floor.

Apparently, King Zahard divided the key into two parts. He gave the first half of the key to the blacksmith Ashul Edwaru who melted it and turned it into 13 Month Series, so that the key would be shared between Zahard and his 12 companions. Eventually, these weapons were instead given to the Zahard's Princesses, who were subsequently made to fight amongst themselves with them. The other half of the key was melted into several crimson rings with the crest of Zahard. These rings were handed to children who inherited the blood of Zahard, whose existence was meant to be kept hidden alongside the rings. Two of these children, Ja Wangnan and Karaka, have been revealed.

It is said that when all of these 'Princes' of Zahard are able to climb the Tower, the door beyond 134th Floor will open once again. Because of this, many speculate who will be the real "Prince of Zahard" that will take the Tower’s last test.