Unlike in other story worlds, there were far too many Lords of Hell in this world.
Relatively speaking, the souls of ordinary people were still limited when divided among them.
One could roughly guess from the souls Wu Heng had consumed while building his hell.
That was why sending avatars into reality to slaughter indiscriminately would be jointly stopped by the other Lords of Hell, because it was digging up everyone's roots.
But "invading reality" was different.
One had to open a passage between one's own hell and reality, then personally hold back the other Lords of Hell's avatars while one's demons or Cenobites, much like forging a hell, continuously extended their hell into reality and carved out a path.
Then, using that point as a foothold, they would continuously spread their hell outward.
Once a hell had fully gained a foothold in reality, its infernal aura would completely alter the surrounding terrain and the forms of living creatures.
Like ink spreading through a pool of water.
The prerequisite was that this drop of ink—the hell—had to be able to fall into the pool. The hell had to reach reality.
And once a Lord of Hell's hell spread into reality, it meant that both aspects of his true body had taken root in the real world.
The other Lords of Hell, however, would be unable to act because their true bodies were confined to hell and their hells had not entered reality.
Even if they sent their respective avatars, an avatar entering a hell already established in reality would be like Baphomet entering Wu Heng's Blood Floss Hell—it would be nothing but suicide.
Every Lord of Hell's avatar was precious.
Most of them had struggled bitterly and finally managed to forge an avatar with pseudo-hell-level strength.
Therefore, once Abaddon Hell