Who is Jack of Diamonds from The Looking Glass Wars and what is their importance?

Jack of Diamonds is the son of the suit family, the Diamonds. Jack of Diamonds might have been Alyss's spouse had Redd not taken over the throne because she is to marry a member of the suit families and he is the only one of appropriate age. Jack of Diamonds is a spoiled young man and is very unpleasant. During Redd's reign he feigns loyalty to both her and the Alyssians, but is really out for his own gain. In the end, Alyss has him arrested for war crimes.