My theory is that each of the six elements is a positive magic type, and can be used against dark magic to a limited degree. Different ponies have different types of magic inside them.Slamtastic said:If it was only Celestia and Luna vs Discord, wouldn't they both have to be 3 elements each? (One for the Earth, Pegasus, and Unicorn parts that make them up?)PBalfredo said:
Some wizard pony in the distant past found a way to turn stones into powerful sources of magic (I'm guessing they're not just containers, they actually generate), and made one of each type. This way any pony (assuming they know how) can wield all six types of positive magic, and mix and match them to create even greater harmony-type magic, without the need to be born with even one of them.
So when Celestia and Luna tried to fight Discord, they could have taken the element stones and divided them up 3-each, which would have given each of them quadruple-magic (assuming they took elements which were against their own type) with a significant degree of harmony, but turning Discord to stone required full six-element harmony, so Celestia and Luna probably needed to team up on one shot.
After Luna powered up with dark magic and became Nightmare Moon, Celestia took up all six elements and used harmony magic against her, which defeated her evil power, but getting beaten only amplified Luna's grudge against Celestia, giving her an evil recharge, so Celestia imprisoned Nightmare Moon.
Celestia hid the Friendship/Magic element, apparently so only someone like Twilight would be able to use them.
Twilight found and almost made the five elements work despite not knowing how, but then Nightmare Moon broke them, knowing that positive magic was harmful to her evil power, and useless for her to use against her enemies.
But the mane cast were living sources of the element magics, so even the broken fragments were useful to them as easy conduits for their own power. Twilight transformed the fragments into magic necklaces.
Twilight's element became a big crown thingy because her element stone was unbroken. In theory, anyone who wears Twilight's crown should temporarily become a capable wielder of Friendship/Magic-type positive magic.
Twilight's first attempt to fight Discord didn't work because Spike doesn't have any loyalty-element magic in him.
In Twilight's second attempt to fight Discord, she made a protective bubble to save her friends, and it fixed part of the ground because it was Friendship-based.