Just after leaving the Blood War Battlefield, Leon thought of a way to expand the scope of the Blood War.
He could easily cause trouble in Aphnas, throwing it into chaos and giving demons an opportunity to conquer Aphnas... If there is a chance to conquer Aphnas, I doubt any Demon Lord could sit still.
If that doesn't work, he'll have to personally go to the layer of the Bottomless Abyss where the Demon Lords reside and create trouble for them. Just a bit more effort.
As for the specifics of causing trouble, Leon hasn't thought it through yet. He's decided to take a spin around Aphnas first, looking for opportunities... After all, he has already undergone Bone Shedding and Rebirth and is no longer a mortal. Even if the gods wish to spy on him, it's difficult to achieve. This is known as being beyond the reach of divine eyes, let alone with the aid of the 72 Transformations.
