Basic Trope: Some Applied Phlebotinum requires horrible deeds to work.
- Straight: Emperor Evulz fuels his spacecraft's Faster-Than-Light Travel engine with children's blood.
- Exaggerated:
- All high-tech contraptions need children's blood for power.
- Not only does the spacecraft require children's blood, but it also needs their bones, muscles, teeth, eyeballs, and teddy bears to work properly.
- Emperor Evulz's spacecraft needs to be fueled with children's blood constantly, even when it's not in use.
- Downplayed: The spacecraft needs a person to power it but only causes non-lethal problems like muscle soreness and headaches. Volunteers aware of the effects can suffice, though eviler characters might find it easier to use slaves.
- Justified: The mental signature of suffering human brains is needed for powering these contraptions.
- Inverted: Joy Engines require Emperor Evulz to do great good to operate.
- Subverted: Evulz has an alternative way to power the FTL drive.
- While cars can technically run on blood, it's one of the worst possible fuels and is a maintenance nightmare. Even distilled ethanol keeps it running far smoother and with greater power.
- Double Subverted: The other source still requires something horrible.
- Parodied:
- The place where Evulz's spacecraft gets energy has a label saying "Insert Child Here."
- Evulz’s spacecraft is powered by Alice’s humiliation. He places her naked in a tank and invites people to gawk and photograph her.
- Zig Zagged: The spacecraft requires human power, but other ways to power it exist. However, it still needs humans as backup power.
- Averted: The spacecraft doesn't need humans for power.
- Enforced: The producers want to show how evil Evulz is.
- Lampshaded: "Why do we need an innocent child to power this spacecraft?"
- Invoked: "And what am I supposed to do with all these useless orphans my conquest has left around to mewl? Wait, maybe not so useless..."
- Exploited: Evulz's requirements for power give him a need to kidnap people and steal resources from them.
- Defied: Evulz finds a different source of power.
- Discussed: "Why couldn't we have done more research on the requirements for Faster-Than-Light Travel?"
- Conversed: "Why does that villain on that show need a human to power that thing?"
- Implied: Evulz is seen strapping a kidnapped child into the ship.
- Deconstructed: Evulz must kidnap many children for power, causing him to reach a 0% Approval Rating after many children are taken from their homes.
- Reconstructed:
- Evulz covers up disappearances with false leads, keeps the children in a top-secret area, and kills them out of sight.
- The souls used in this manner agree to be used this way, and even encourages the user to use more of them to defeat the Big Bad.
- Played For Laughs: The machine runs on Hamster-Wheel Power/Black Comedy.
- Played For Drama: Evulz goes on a crime spree to kidnap children for power.