Teenage Mutant Ninja Turtles 2012: Beneath Silver Armor-The Flame Princess.

This is a feudal fantasy Teenage mutant ninja turtles (2012) story.

Splinter is scavenging for food for his 3 months old turtles, Leonardo, Raphael, Michelangelo and Donatello. When I man approaches them saying "come with me" Splinter was weary of him, but followed him anyway, the man named introduced himself and built a secret area beneath his castle for Splinter and his turtles, and Kyo says he will help out Splinter and the turtles and keep their secret.

The turtles reach 15, Splinter finally let's them go to the surface and Kyo appears asking them for a favor. Splinter says yes and Kyo asks them if one of the turtles can be his daughter's appointed knight and the rest of the turtles can be her guards Splinter hesitates but eventually says yes.

(Credits to artist. It's just a placeholder until I can find someone to draw a cover.)