Making Side/Non-important-to-the-main-Storyline Characters Relatable

Storycrafters spend hours, even days making their main characters relatable to their readers, but what about characters that are not main? Let's take Haldir for example. In The Lord of the Rings: The Two Towers he has a relatively short role. He shows up right before the Battle of Helm's Deep with an army of elven archers to aid the Rohan warriors in defending their home. He meets his end at the hands of Uruk-hai during the battle and has very little screen time, yet we still find his end sad, even though he did very little and wasn't even in the book. So what makes him a relatable character? The first, probably most obviously, is a scene where Aragorn is trying to persuade King Theoden to send for aid. Theoden answers with a question, "And who will come?" The movie makes a point that there is no one that can help them. They are all alone in the world against the legions of Orcs. Haldir then shows up with his elven archers and answers Theoden's stunned inquiries as to who he is with, "We are proud to fight alongside men once more." Haldir helps Rohan when no one else would, and we can relate to that. More close to Haldir himself are the repeated scene where Aragorn's close friendship with Haldir is made clear. Even when Haldir meets his end, he does it in a poignant way. The orcs have breached the walls, and Haldir alone stands on the wall tops fighting as everyone retreats until an orc comes from behind him and stabs him through the back. Aragorn charges to rescue his friend, slaying his slayer, but it is too late. This is even more relatable than Theoden receiving the reinforcements. We've all lost someone that we loved, and we can relate, if not directly to Haldir, Aragorn's loss of Haldir. There are tons of things you can add to side characters that make them more relatable. In my story Eyes of the Dragon I tried to make Icarus more relatable by making him a freedom fighter. He fights for his people and for his country, even striking a blow against his country's tyrants with his dying breath. Icarus does almost nothing to further the main plot, yet people can still find his character emotional (At least I can, I haven't shared the story with others yet.) even though he isn't essential to the story.