The frontline is called the frontline because battles frequently occur here. They are stationed here to guard against a ninth-tier Demon World, as the demon worlds are incredibly aggressive.
Moreover, this world reaching the ninth tier poses a significant threat to Earth.
The most critical aspect is, with the Abyss supporting this world, the danger increases dramatically. Du You's initial attack, which drew in five powerful ninth-tier entities, clearly indicates the severity of the situation.
It is precisely because of this that Earth has yet to confront this place head-on, avoiding a decisive battle to minimize potential losses. Earth, with its relatively short history and lack of deep foundations, cannot act as recklessly as the Abyss.
Thus, this location remains a crucial frontline region for Earth, constantly patrolled by ninth-tier powerhouses.
