Twilight, after realizing some faults that the elements of harmony have, such as the fact that they only work if all six of them are together, casts an enchantment on the element bearers to make them more independent of the Elements. By drawing on powers that the Elements dictates as another side of the corresponding bearer. This leads the Mane six to find out that there are many hero's and it will take the newly acquired powers of the bearers of Harmony to protect Equestria from the Evils they awoke with this spell.