According to most ancient of Slime legends millennia ago when the Great Slime Father and Great Slime Mother first formed from the dust of the planet they had three children. As the planet started to be occupied by others (due to the opening of the rips in space and time) the Great Slime Mother realized they’d need to keep track of all the magic coursing through their planet for the safety of all, so she tasked her first born boys with cataloging these spells and items.
As they acquired these incantations and enchanted objects their powers grew to enormous levels, and the three Magi realized they were far too powerful to remain in normal Slime society so they retreated to the woods. Living in cave deep in Barrwood Forest these three Magi stayed away from the other inhabitants of the planet, only appearing to those who held new magics for them to hoard. The various magical currents flowing through their bodies has kept them alive over the billions of years since their birth. They are some of the most powerful beings on the planet, and they have no allegiance to good or evil. However they have of late been helping Prince Algor for the good of the entire Planet. Many have spent their entire lives trying to find the cave of the Magi and steal its secrets, but none have succeeded (and lived to tell the tale) thus far. The Elder Slime Magi, having not been seen by anyone that lives are looked at as legends on Jalldoon, and many people consider them to be just a colorful element of the most ancient Slime myths.