* FridgeHorror: So, apparently everyone is matched according to genetic compatibility, rather than preference. This obviously means a person of the opposite sex. They have no choice in this, and it's permanent. What happens to homosexuals?
* {{Ship To Ship Combat}}: Team Xander vs. Team Ky, with Cassia/Ky being the {{Fan Preferred Couple}}... in a book about how matching others is wrong, meaning...
** DoNotDoThisCoolThing
* {{Tear Jerker}}: Grandfather's death.
** Also [[spoiler: Vick's sudden violent death]] in ''Crossed'', especially when [[spoiler: Ky]] carves that little fish for his gravesite.
* {{Iron Woobie}}: Ky.
* XMeetsY: ''TheHungerGames'' meets ''TheGiver''.