Grand Reveal (a)

Sometime later, once they finished eating, Theo started to explain everything about this place, "I will start from the very beginning, so listen carefully. As you all already know, about ninety years ago, many spatial rifts opened up in space, allowing beasts to invade our world. At first, we only encountered demonic realm beasts, but as days went by, more and more powerful beasts entered our world.

"Do you know why? It's because, in their initial stage, the spatial rifts would've shattered if anyone above the demonic realm used them to come to Earth. Over time, they became more stable by absorbing energy such as magic power from the surrounding; ultimately, even beasts at the king realm are now able to use some of them to invade planet Earth. But that's not at all. After ten years, four spatial rifts will become strong enough for beasts' gods to use them!"