A character does not feel complete if you do not show a full range of emotions in their story.
If you don’t show us what makes them afraid, what drives them to rage, what makes them smile softly, what makes them laugh uncontrollably, what has them brought to tears, then we don’t get the full picture of how that character would act in any given situation.
Even the tiniest, briefest glimpse of any of these emotions fills them out completely - if they only seem mildly sad for about two seconds about something and then go right back to being their smiley self, that STILL tells you about the character. It tells you they might repress their emotions, or feel very low emotional attachment to things. Those two seconds matter.
That being said, Elfilin shows anger exactly once in the entirety of his debut game, and during that moment of anger he is screaming at the top of his little lungs and hitting someone with a truck. And I assure you, that DEFINITELY tells you something about Elfilin.
