Byleth & Shez

Byleth is often shown to lack emotions, particularly towards the start of Three Houses. As the player progresses through the story, some characters will point out that they are smiling more often. Byleth will also display other emotions, such as anger or disappointment, during story progression. Their personality is ultimately dependent upon the player's actions and dialogue choices; Byleth can be quite caring or indifferent, though rarely malicious.

Befitting of their status as the player avatar unit, the above serves to make Byleth a blank slate the player can easily project themselves unto and deepen the connection between them and the unfolding narrative.

Shez is driven by their desire to defeat the Ashen Demon throughout most of the game. In order to achieve their goal, they are often seen training. Despite this, they reflect on their goal to defeat the Ashen Demon, and even question Arval when they push them toward that goal. Nontheless, for most of the game, they trust Arval, often bringing up suggestions made by them to their respective army's leader. They are often very reckless, acting before thinking about the consequences of their actions, even if that may cost them their life.

Throughout most of their support conversations, they support their partner with their issues, demonstrating their compassionate side. However, they make it clear that as a mercenary, they cannot afford to demonstrate the same attitude on the battlefield. Although they understand why some of their allies don't trust them, they often lament the same fact and wish for more trust from their allies.