Royal power whose sibling rivalry between Maestro and Formidable played out through Carl's crew.
The Skull Empire's internal politics shaped the trainyard endgame. Carl concluded that Princess Formidable handed Katia Grim The Bolt of Ophiotaurus chiefly to send a message to her brother Prince Maestro, not because she expected the crawlers to kill him — and that the bolt could not have hurt him anyway.
Maestro, having seized unlimited power and squandered it, was driven into The Abyss and teleported to safety, after which Carl believed he abandoned his sponsorship, blunting the damage in the pit. Princess Donut mocked him for wasting the opportunity, and Carl noted that even the mom would have done a better job, but she had died instead of him.
Sponsoring royal house whose sibling feud is fought partly through the crawlers.
Also appears in books you've already read — spoiler-safe to their endings: