I know this is cliche but whatever.
Long ago, on October 31st of the year 2016, a meteorite crashed. While it is true that the Earth receives many meteorites, none but this one carries a parasitical virus, which changes genetic code. After being discovered, scientists realized to their dismay that this virus gave humans the ability to manipulate the world with magic. The … government tried to hide these secrets, yet the news broke out, and the world scrambled to get ahold of the virus. Not only does the virus transmit through blood, it also transmits through meteorite dust. With all the scientists affected, it was not long before the entire world soon got their hands on a Special Ops magic division. Now WWIII is about to break out and only two people can stop it. First, the 18-year old apprentice astronomist serving an internship, who was the first to get the virus, and thus has the most powerful magic attribute, one of light. The other, is the only person to be affected before birth, and has the other strongest magic, one of darkness. This makes the girl grow to 18 within 18 days. The two meet up. Together they declare their neutrality and their stance, and fight to prevent the war.