Gatekeeper (Sander Sides Gatekeeper AU)

Y/n and Thomas are a rare type of people. They have embodiments of parts of themselves that occupy a plane called the Mindscape. It is connected to Earth through gateways that link to people like Y/n and Thomas. Y/n was born into a family these people, known as Gatekeepers, and knows that her and her sides have to protect the inhabitants of the regular world from the creatures of the Mindscape.

Thomas's bloodline, however, has not seen a Gatekeeper in centuries, and has since been recorded as a dead bloodline. And so when Thomas's sides develop into their own characters and (unintentionally) reveal Thomas as a gateway, he is left unprepared and vulnerable.

Good thing Y/n steps in, Yes?