Their creations, Titanspawn, if you will were powerful creatures prone to violence and destruction like thier creators - however some for one reason or another were different. This group of Titanspawn rse up against the Titans in war and defeated them - imprisoning them for eternity. They were the Gods. Your parents.
The names and myths of them are varied and are imbedded in Human History - though their presence in the World has diminished over the centuries - they are active still. A fact your other parent can attest to.
Despite their overall withdrawal from worldly affairs, the Gods are compulsive meddlers. Though seldom taking direct action against one another or overtly guiding the course of humanity, the Gods still possessed a means of interfering in human history, their Scions.
In due time, the Gods retreated from the World. With the titanspawn threat wiped out the corresponding rapid growth of human civilization and the conflict between nations threatened through the chains of Fate to draw the pantheons of Gods into war. To avoid this eventuality, the heads of the various pantheons met and agreed that the Gods should leave mankind to its own devices before the massive Fatebinding effects either threw them into conflict or changed them beyond all recognition. In response, most Gods retreated to the Overworld, only visiting the World occasionally in mortal guises.
Over the millennia since the Gods’ retreat, a myriad of Scions have lived and died, most ignorant of their fantastic origins. However, in every generation, a few Scions worldwide, seldom more than a handful, receive a Visitation from their divine parents, unlocking the power of the ichor flowing through their veins. One or two in a century might even be gifted with Birthrights.
All that changed with a single event, the escape of the Titans. Somehow sundering their Underworld prison (and in the process, damaging the realms of the dead), the Titans have reentered the Overworld after eons of imprisonment, hungering to regain their former rule and revenge themselves on their wayward offspring, the Gods. While a war between Gods and Titans rages in the heavens, the Titans have begun seeding the World again with their spawn. In response, the Gods have begun visiting their Scions in greater number and arming them so that they may stop the titanspawn from establishing a beachhead in the World of men."
Taken from a briefing by Ambrose Milan to Leo, Manny and Jacob on their way to the North Sea - January 13, 2012