@0DeathTheKid,I Think the guys right. when i potted my karma orb i got a 12 m atk pot,BUT I THINK ITS A GLITCH CUZ ITS M ATK AND ITS A RARE it should been a legendery.but atm it does boost my atk range! EPIC!
You can purchase all available Luminous orbs from the Ellinia weapon & armour shop. They are available in four level intervals - 10, 30, 60 and 100. Though the only practical orb of the available four is the level.100 Karma orb because it's the only orb that has 3rd tier potential.
I'm not quite sure if you can potential the first three orbs though. Either way, you'd be better off to potential (and cube) the Karma orb.