The legend of Zelda: Twilight Princess

[DamnthatDavid]

On My first weekend back from bootcamp I went to a friends house and we watched cheesy movies, and played Gears of War. My friend had also brought his Nintendo Wii. Seeing how he was busy mastering Gears of War, I borrowed his Wii and Zelda. The game was freaking awesome, just finished it today. 5 days... Majora's mask took me longer.

Anyway, can anyone tell me at the end why Zant did the Neck Crack and Ganon mirrored him and died? Only thing I'm not getting.