You can use the Ether Mill in the basement to strengthen your gear. What is Ether? Magical power that resides within gear.

Extracting Ether

Extract ether from your gear, and use that ether to strengthen your other gear of the same type. You can save up to 9999 ether per type. *When you extract ether from your gear, that piece of gear will be lost.

You can use ether to strengthen your gear. You will need money and ether to strengthen your gear. *The stronger the gear, the more ether and money will be required.