Lucy molds her impressionable "older" brother.
Now that he has a Humanich sister, Ethan has been doing everything he can to make her proud—including changing himself to be more like her. Lately, Ethan has shown signs of a more pragmatic personality and has developed a general distrust of authority, traits that only intensified after he shared information about Molly with Lucy.
When Lucy inquired about Molly's visitation time, Ethan told her that Molly wouldn't be seeing him until she fully recovered from her sickness. Doubtful of the story, Lucy told Ethan that humans aren't meant to be trusted because all humans lie. In an instant, Ethan's demeanor shifted.
Later, Ethan came to Lucy with an invention of his own. He had created a robotic spider, fully equipped with a camera, that he and his sister could use to spy on the humans while they were powered down. The once sweet, little boy who enjoyed playing with robots is now scheming with his authoritarian sister and creating machines of his own.
Could Ethan's transformation be permanent, or is he simply looking for affirmation and a sense of belonging?