I, Frana Shimi, have speculated for the Lords of War an answer for a new type of container. The problem that you had presented to me was the ability to seal off the very power of the elements. No material has the ability to hold all of the powers of the elements at one time. I believe though if you were to create an unfired medium container and then
fire it with two high quality firing sheets covered in Multielement glaze it would create an invulnerable container. To make the Multielement glaze, you will need to mix together the four base element glazes: windy glaze, aqua glaze, earthen glaze, and magma glaze in a glaze mortar. I dare not imagine why you would
need to combine the quintessence of the elements, or what you would do with it. Please consider my time here spent well, and set my soul at rest. I have toiled here for long.