Kapitel 1927: The Allied Army Of Nations.

9 Crowns was already too powerful. With the tower of realms, he would become even more powerful. So they had to stop him now with all they had. All the gods were of one accord about this.

The gods were also very determined to stop him so much that they pulled their heroes from the fight for the Mortal Blade and made them target the Orc Empire of the 9 Crowns. 

They understood that they couldn't threaten the 9 Crowns in the divine plane anymore, so they made up their minds to uproot him in the mortal realm completely. That meant that even the gods joined their army in its march towards the Orc Empire. 

All of this was not a secret to Legion. They could see the gods taking such actions and hear them announcing the alliance of gods against the 9 Crowns everywhere in the divine realm.

They also received numerous messages from other gods threatening them or demanding that they surrender. So they had some time to prepare for this.