Invidia is a world of malice and various magic systems that caters to many transmigrators and reincarnators.
Various planes interconnect with this world, but Battle Aura or Ki is the most prevalent energy used in this plane.
It is easiest to use and doesn't have all of the requirements of other energies that could be used.
When using Battle Aura, aka BA or KI, there are ten power grades.
Tenth grade is the lowest, and first grade is the highest.
However, because of this favored energy source, life is incredibly harsh for humans, especially when monsters are typically two to three times stronger than humans on the same power level.
Also, when you got a bored ROB will be watching your every move and tinkering with things.
Things can get pretty nasty, be it for Jack or those around him.
So expect bloodshed, betrayals, and people doing what they can to survive, as the ruling nobles are the only ones living better because of their 'histories.'
Hopefully I can manage to work on this while continuing my other novels.