Roylia

Roylia is the het ship between Roy and Cecilia from the Fire Emblem fandom.

Canon
Roy is the protagonist of Binding Blade, and Cecilia is Roy's professor, a talented mage and General of Etruria. They first met when Cecilia is hired to teach Roy and Lilina the basics of battle and politics to make them prepared when they inherit their respective kingdoms. At this time period they develop a close bond in which Roy admires and look up to her. Cecilia's opinions have strong influence on Roy's way of thinking.

Cecilia eventually need to leave the teaching office when she is chosen as the next General of Etruria. When Roy recaptures the kingdom of Ostia after a coup, he asks Cecilia help to assists him with protection with her reinforcements, then when Cecilia need to leave again, he entrusts her with the care of princess Guinevere.

Cecilia founds the revolutionaire group, and is eventually improsoned by the King Zephiel. Roy then appears to liberate her from the prison and they fight side by side to save the world.

Their conversation show that Roy blindly trusts Cecilia's decisions and see her as someone who knows things. Cecilia however wishes to see Roy flourish as the new leader of the army and demonstrates that he and she are no longer a teacher and student on the battlefield, and that he has things to teach her as well. They finally realize that they are both on equal footing and can fight side by side and learn with each other.

In the end of the war, together they both make an effort to reconstruct the lands destroyed by war. Cecilia helps to reconstruct her homeland Etruria, gaining the tittle of "maiden of Etruria", and Roy help his dukedom Pherae. They eventually marry, making her the next duchess of Pherae.

Fanon
Cecilia is one of the most popular ships for Roy and one of the only Roy pairings that gets attention other than Roylina. Their dynamic is portrayed as mature woman x teenager boy that has a crush on his teacher and eventually gets her attention back. In fanfictions and memes, Cecilia is often portrayed as a more experienced woman who introduced teenager Roy to his sex life, teaching him all the sexual secrets.

Trivia

 * Roy is 15 in the beginning of the game, while Cecilia is in her 20's - her exact age is not known.