Kaarin was a great mage who live 900 years before the current time. He had mastered a class-10 magic which ws generally said to be impossible for humans.
in his old age he settled down in area what is currently the Renkal region. One day his son came with his grand son who had contracted a serious disease. Kaarin tried everywhere and could not find a cure. thus he began his own research and in the end he created a tree which cured his grand son.
It is not clear how the Kaarin tree was created. Some rumours think it was summoned/ The efficacy of fruit of Kaarin tree is said to surpass that of the high priest.
When Id reaches the tree he finds it dead. It is told that the tree died after a lord killed all of Kaarin's descendent to monopolize the tree.