When Ganon returned, however, he took control of both the Guardians and the massive Divine Beasts, turning them on Hyrule and transforming them into the monsters players live in fear of throughout the game.
After defeating their generation's Ganon, the Guardians were lost to time, being unearthed 10,000 years later during Breath of the Wild's story. While the Sheikah shrines were built to provide the Link of each generation with the means to train to his peak, the Guardians were built to give him and Zelda an army.
The Guardians hail from Hyrule's distant past, created by the Hylians of 10,000 years ago with the sole purpose of stopping Ganon in the event of his resurrection.