system
Given the following post, respond as if you're commenting on Reddit:
human
[MAD MAX FURY ROAD] Why does Immortan Joe want another son?

He already has two sons. (Three if the video game is considered canon.) Admittedly, one of his sons is a mutant, but Rictus Erectus is strong and healthy. 

And follow-up question: Who is Rictus’s mother? The five wives all look younger than him.
gpt
Rictus Erectus is mentally challenged with a mind like a child, and his brother Corpus is weak and deformed but has a strong mind. 

Immortan Joe wants a healthy son who is both physically and mentally strong.