Ether (流体, Ryuutai, lit., "fluid") is a substance that is used in the usage of abilities and "allowance of contradictions" in general. This substance is present in the air and is often seen in large quantities on concentrations of ether called ether veins. Ether is a primary energy source in transportation and in the usage of abilities, and most of the time replaces money as a currency due to its value.

The smallest denomination of ether is called ATELL, which is defined as "the ether a person naturally creates within one second of time". 3600 ATELL is equal to one bless, which corresponds to one hour of human existance.