Lord Rabbit?

Usually, 100,000 years after breaking through to the Mountain River Tier, one would have to join the Two Realm Battlefield.

However, some people were prodigies who might have advanced into the Sun Moon Tier after 30,000-40,000 years. Hence, there was a rule that those who had advanced into the Sun Moon Tier had to enlist in the army to resist the enemy forces within 1,000,000 years of their breakthrough. What about those that were slightly more genius, and had advanced into the Heavenly Body Tier within 1,000,000 years after that?

Then they would have to join the army within 10,000,000 years from then. In short, you had to perform your military service unless your abilities were strong enough to oppose the two great Empires.

This time limit was meant to give geniuses a long enough time for them to develop and grow to avoid them dying needlessly on the Two Realm Battlefield.

The most useful item on the Two Realm Battlefield was merit points.