Contractual Genre Blindness: The main reason why he didn't realize Alice was the Monster Lord despite overwhelming evidence before The Reveal.
Artistic Age: The game specifically goes out of its way to never directly reveal Luka's age, with the CGs representing him also varying with each artist (See Art Shift).Ancestral Weapon: The Angel Halo was originally carried by Heinrich to defeat Black Alice 500 years ago.Despite this, Luka can't help but wonder if humans and monsters might be able to get along.
The Goddess Ilias appears to him in a vision, urging him to become a Hero and slay the Monster Lord in order to drive back the hordes of monsters that plague the world. The protagonist of the series, Luka begins the story in Ilias Village.