The unstable factor was the poisonous mad dog. He was big trouble for all the creatures in the Dusk Soul Forest. No one could kill him, and he would randomly attack just about anyone.
Yagon was worried that the dog would join the other side.
"Are you talking about the poisonous mad dog?" Himmel Soan asked.
"Yes! Things will be much more complicated if he turns against us!" Yagon didn't want to bring up that dog, but he didn't have a choice. In the current situation, the dog might become the deciding factor.
If he joined the tiger, Yagon wouldn't stand a chance. Even if the dog didn't join the other side, he might still stir things up. As for Lumi, that creature was so mysterious that even Yagon didn't know where it stood.
Lumi was probably one of "them." What would "they" do in a situation like this?
"The poisonous mad dog is a peculiar creature, but you're all wrong about one thing. He's not crazy.