With the support of the Netherworld Mecha, the Rats advanced like a hot knife through butter.
Even though after a hundred layers, the subsequent Abyss Planes started to have Lords, their power was no match for the Mecha summoned by the Rats.
Because these Mecha all come from the Third Holy Prison of the Netherworld, established by Lette, to consolidate the Holy Prison of the Nether Beach.
And the Mecha there are not the same as ordinary Puppet Mecha.
They are independent entities with Mechanical Souls, powerful beings that survived the world-ending crisis.
The reason why the Rats could control them is also due to the Power of Profanation that both sides possess.
It's not at all like the Demon Gods speculate, as if having money would enable control.
They are willing to offer money, but Lette is unwilling to let the Mechanical Species earn that money.
