Promised Number

The Promised Number (約束の数) is the long-term goal of the Roidmudes which will finally allow them to achieve their ambition of overthrowing the human race. Mentioned throughout the series, it is eventually revealed by Heart to be a gathering of Roidmudes who have achieved Super Evolution, with the quota being four.

Freeze was the first Roidmude to achieve Super Evolution, however, he died with his Core following his body's destruction by Drive Type Tridoron. Soon after, Brain became the second to achieve Super Evolution and, though his body was also destroyed by Drive alongside Mach and Chase, his Core was lucky enough to survive and escape, being begrudgingly preserved by Medic despite her hesitation to restore him due to their mutual disdain for each other. With Heart achieving his own Super Evolution, he noted that only two more were needed to be found to join himself and Brain in the Promised Number.