A long time ago, there were six Elementals. Fire, Water, Earth, Wood, Wind and Mineral. Fire and Water were at war with each other, so Fire teamed up with Earth and Wind while Water teamed up with Wood and Mineral. They battled for thousands of years until a new Elemental appeared: Ice. Ice was always on Earth, but no one noticed him due to the fact that he was a peace-loving Elemental, unlike the others.
Ice froze the Earth so every Elemental lost its powers. (This time is known as The Ice Age) Realising that Ice was the most powerful Elemental, the other six Elementals decided to listen to him and stopped the war. Ice went back into hiding and unfroze the Earth, returning the Elementals their power. The seven of them lived in peace for the next few decades.
After years and years, the Elementals decided to find their descendants. Fire, Water, Earth, Wood, Wind and Mineral found their descendants easily, and long later, all of their descendants met again in a school called Hogwarts. Fire found Hermione Granger, Water found Theodore Nott, Earth found Ronald Weasley, Wood found Blaise Zabini, Wind found Ginny Weasley and Mineral found Pansy Parkinson.
Fire and Water often fought against each other, but as cliche, as it sounded, Water fell in love with the fiery temper of Fire and Fire quite liked Water's git-like attitude. When they announced as a couple, the same thing happened to the rest of the Elementals: Earth fell for Mineral and Wood was hopelessly in love with Wind. All was well.
As for Ice, he was very picky with his descendants. He couldn't find one in all these years. There was a girl in the 1700s who was near perfection, but her personality was too kind. Very un-Ice like. Therefore, Ice gave up finding. He visited his friends in Hogwarts and saw that his friends were living happily together. Thinking that he ought to just let his powers die with him, he was about to leave when he found the perfect descendant.
He was arrogant, quick-witted, cool and handsome, everything Ice hoped for (even better). But the only problem was that the boy was a teenager already. Yes, normally a person is born with the powers of an Elemental, not receiving the powers in the middle of their lives. However, Ice decided to break the rule and created an exception: The boy would receive his powers after his eighteenth birthday.
Ice was so excited that he forgot to tell his friends. The other Elementals never dreamt that Ice would find his descendant. After all, he had tried in vain for the past centuries. They lived in peace...until the boy's eighteenth birthday, of course. And Ice's descendant happened to be the most unexpecting person of all...