Iris' mind was plagued with the thoughts of the possibility of Cane dying once the lycan left him. It scared her so much more than anything and she was unable to think clearly.
'Do you think I will stand a chance in a direct battle with a dark sorcerer without the lycan's power like what happened in the mountains?'
The answer was an immediate no. It was proven that Zeke and Cyan were Decratic's worshippers and both of them were mind controllers. How was one supposed to fight someone who could mess up their mind?
If Iris calmed down enough to think about the matter thoroughly, she would have realized what Cane said was true. The best chance they had to fight them was by using the lycan's power and exploring more of what this cursed creature could do.
But then, this decision was a double edged sword, since the world was not such a welcoming place for a cursed creature like Lu.