"Hey, Leon," Anna called out Leon's name. "Thank you for helping us out. If it weren't for you, none of this would have happened so smoothly."
Anna now thinks that it's good that they got Leon involved because if she or her brother went off and talked to Isaiah, face to face, then hearing about their uncle's plans, Anna thinks that she and Aaron won't be able to control themselves and killed Isaiah and Ilana right at that moment.
"Anna, saying thank you to me is not enough! I need more than that!" Leon pouted like a little kid. He was feeling upset with the twins earlier, but after what happened with Isaiah and Ilana, Leon thinks the same way as Anna.
It's a good thing that they got him involved. Even though the twins show that they are calm and rational all the time, he thinks that the twins cannot control their anger if either of them is on the same spot he was in earlier.