Eternia Crystal

The Eternia Crystal is an event-summoning item. When used in the Eternia Crystal Stand, the Old One's Army event begins. The Eternia Crystal is purchased from the Tavernkeep for (pre-mechanical bosses),  (post-mechanical bosses), or  (post-Golem).

Tips

 * Players may wish to stock up on Eternia Crystals before defeating the mechanical bosses, in order to save coins.
 * Due to the price increase, it is possible to buy Eternia Crystals beforehand and sell them after the battles, netting a total profit of per crystal (This no longer works on desktop; the price you sell the crystal for is based on the price you bought the crystal for regardless of which bosses you have defeated).
 * This is not possible on the ; they sell for even post-Golem.