Each tribe, regardless of size, could send out one barbarian under the age of thirty to engage in magical combat for the twenty-five spots.
That is, if the demon beasts wanted to enter the "Dragon Gate," they had to join the major barbarian families and cooperate with them wholeheartedly.
Gradually, the form of cooperation called Sacrificial Spirit emerged.
Demon beasts looked for suitable barbarian families, and barbarian families likewise searched for appropriate demon beasts.
Once there was a mutual agreement, the demon beast would become the tribe's Sacrificial Spirit, protecting the tribe and sharing its fate.
In return, the tribe would do everything in its power to win a spot for their Sacrificial Spirit to enter the Dragon Gate.
The stronger the tribe's power, the more chances it had to secure spots for their Sacrificial Spirit in the Dragon Gate, and the more chances the Spirit entered, the greater its potential became, which in turn benefited the tribe as well.
