Djehai, being the awful and narcissitic demi-deity he is, decided to make his own son for... reasons. This was how Agiti was 'born'. After some time, Djehai became jealous of his creation since Agiti was considered prettier. Agiti decided Djehai was a crazy and unpleasant creature and fled the moment he could. Agiti is said to travel world now, and is the father of the branch of magic called korrisi, focusing the 'spark of life' to protect or heal.
Korrisi is a magic exclusive to garrans, no human nor pora have ever been able to duplicate it. Drawing forth from their own kor and the traces of it around them, a user of this magic can summon blinding sparks of fire to burn their foes, or create a tepid opalescent pool of liquid in their hand to heal the cuts and stabs of their companions. Rumors are whispered of darker capabilities that Agiti forbid his students from learning, such as mimicking the capabilities of varke.
Practitioners of the darker arts of korrisi have discovered how to mimic the kor-sucking abilities of varke... and also what a glut of kor does to the mortal body. Varke naturally use up the kor they feed on, the living do not. Burning with the stolen essences of hundreds or more, they become twisted and mutated creatures with the strength said to rival the most powerful varke themselves.