Overtone

The Overtone is a form of powerful, supernatural energy that exists parallel to the physical universe. Large spikes in oscillation are necessary to break the barrier that separates the physical world from the Overtone. The necessary oscillations most commonly come in the form of radiation in combination with sound waves. IDOL Suits can emit infrared radiation while focusing the oscillating forces generated by an IDOL's vocals or body movements into a spike that can break the Overtone barrier. Once broken, an IDOL Suit molds the Overtone's formless energy into a manifestation called a Concept.

History
The Overtone was discovered by the Japanese in the aftermath of the nuclear bombings of Hiroshima and Nagasaki. The radiation and loud noise of the nuclear bombs created various uncontrolled Concepts which posed a danger to the surrounding Japanese people. The occupying United States military began research on the Overtone. A rogue American scientist defected with the Overtone research and founded the first Legion, whose super-soldiers could harness Concepts as weapons. These soldiers were the first IDOLs. During the Cold War, the various Legions in Japan effectively removed American military presence from the Eastern hemisphere. During the Korean War and without American assistance, South Korean scientists reverse engineered the Overtone technology, and used IDOLs to unify the Korean peninsula despite heavy resistance from Communist Russia and China. With IDOLs securing their national borders, Japan and Korea grew to become world powers with the latest advancements in technology.

Visual
After the discovery of the Overtone at the end of World War II, some individuals have been born with the ability to see the natural weaknesses in the barrier between the Overtone and the physical world. Called Visuals, short for visualizers, these individuals can allow themselves or others to utilize Concepts to their maximum potential by identifying the moment the barrier is at its weakest. Since their discovery, they are especially coveted by Legions who actively seek them out for their IDOL combat potential.