Standard Zakkra Index: The Standard Zakkra Index is used to quantify the power released by the full energy burst contained within one gram of Standard Zakkra Crystal.

1 Standard Zakkra Index = 1 kilogram of standard TNT explosive equivalent.

The Earth Federation uniformly refers to innate-level martial artists as Fighters, dividing them into nine tiers based on the destructive power unleashed by their full-force strike, with each tier named after one of the nine planets in the solar system.

Mercury: 100000000－999999999 Venus: 10000000－99999999 Earth: 1000000－9999999 Mars: 100000－999999 Jupiter: 10000－99999 Saturn: 1000－9999 Uranus: 100－999 Neptune: 10－99 Pluto: 1－9C