"And why did you do that? Obviously, you don't need to fight him, he loves you so much, Vernon."
"Because I want to free you from him," Vernon replied without thinking twice. "I don't want you to get hurt anymore, and the only way for that to happen… is to topple him from his throne."
Vernon decided not to say his original motive. Initially, he returned to New York and launched his slow revenge because he hated both Chloe and Vincent for making him live in a nightmare.
But his motive changed after he got closer to Chloe, and he soon realized that he truly could not help himself from falling in love once again. Now, he fell in love so hard that he became distressed by the smallest pain that Chloe experienced.
He had nothing else in his mind other than protecting Chloe from that monster, even if it would cost his fortune or life.