Ajin

Ajins are considered an exotic race. They're completely immortal, they cannot die permanently in anyway. When they die, they'll revive shortly (around 5 seconds) at the same spot. Ajins are dangerous and should be avoided. They're kept locked up and are the best race to use for experiments because they cannot die.

Background
Ajins were the work of Satan. It is rumored that Satan creates one Ajin by using 1,000 Human sacrifices. Ajins are sometimes considered demons but scientifically, they are their own race.

Abilities

 * True Immortality - When they die, they'll reawake in the same spot shortly after (usually around 5 seconds). This Immortality is considered stronger than a God.