What makes characters memorable?
This is an open debate, give your answers, make your case, but be open to others suggestions. You might think you are right but that doesn't mean everyone else is wrong.
However, here's just a few things I can think of off the top of my head that could help:
Relatable - is your character a being with flaws and live a life of personal problems that they slowly overcome or accept? Do they have goals they want to achieve?(do your readers spend time with and get to experience these characters dealing with those flaws or problems?)
Unique - is the character unique or different from the 'norm'? (Usually a side character, but if you can enter the mind of someone like this I tip my hat to you)
Surprise - does the character perform an amassing or sudden surprising thing or feat?
The more you portray a character deviating from the norm the more memorable that deviation becomes. Like in this red-less setting if every character brought up the fact that that one had red hair like a running gag it would become even more potentially memorable, because it has an impact on the world, and things that have an impact on the world are “extremes” in their own way, and you’re given more reason to care and remember that red hair fact for how it influences how the plot progresses. Like that one arc where our red head needs to disguise themselves in a land that made wearing hats illegal.
Normal things can also be extreme. Despite all of us being tired of the boring “average”, a thing COMPLETELY average to the level pf absurdity is also a kind of extreme. Most things can be generally average, but they always diverge in detailed ways, which is why cliches are unrealistic even if they aren’t always completely untrue. So when our redhead travels to the continent of red heads, they stand out because they are the only one who still finds red-headedness special, the only one who cares. Red heads have their own cliches, and if they’re the only one playing the archetype as straight as can be they stand out from all the other red heads who don’t fully match that image.
Seeing a archetype or cliche in real life, exactly as it is conceptually portrayed in every way, is rare, and it stands out as a unique personality at times despite being perceived as something boring. Before something is so average it is boring it always has something at it’s core that is compelling, and being true to that core can be very engaging in a world where what made that old archetype special has been lost sight of. Otherwise classics being remade wouldn’t ever work, instead of just being unlikely to work.
Dynamism always stands out more than passiveness. A character stands out for their actions more than they ever do for their characteristics. A super edgy apathetic character who doesn’t care sounds very different at first, but then you realise they don’t actually DO anything, they aren’t driven to anything. And that’s more boring than having an old trope played straight will ever be.energetic characters are inherently more engaging (you can still do enthusiasm in a way that drives readers away) and characters that strongly desire things, have a burning need, those characters create the most change, and impacting the plot is impacting them being memorable.
One thing you need to keep in mind also is clarity. If you can understand something, you can remember it. A character might be super courageous, but if the reader is never made to realise how courageous they are that fact never a contributes to them being memorable. Character traits are like an argument, you don’t want to do anything that might undermine that image of what traits the character is supposed to have, even if it takes giving them an exaggerated personality at times. Giving both sides of the argument takes a more careful balance.
Our heroic red head is courageous, but also just a person as well. They still cower in fear when they are scared. If I had told you they were extremely brave, and then proceeded to only show you how they cower, you would feel like the character isn’t very consistent, and isn’t very clear. The boundaries of this character isn’t presented in a way that you can make prediction using, because their are inconsistencies that are not properly explained. But our little hero still trying, not running away even as they are frozen in terror, wanting to overcome that fear and charge in. Finding the monsters that they can fight against, doing their very BEST. That’s courage. So you can show how they aren’t brave, but it needs to be done very carefully and fully aware of how it impacts the clarity of the character in the reader’s mind.
A character doesn’t need to be fully clear the whole time either, just at the end, or everywhere except at the end. If one thing ales everything make sense in hindsight, that makes a memorable character even if they were completely opaque for the rest ofthe book. Also, a character you fully understand except for one choice they make one thing they do is also memorable. Because you know them and what they’d do clearly, but something made them do something else. They might be opaque to you for that one thing, but the rest of the time they are so clear that it actually just makes them more memorable.
Make your characters weird, make them earnest in being their purest self, make them eager and driven, and make them influential, that or mysterious.
What makes a character memorable is contrast, and that can be done by making the other characters different compared to them as easily as it can be done by making them unique. Make them important, give them extremes. Develop clear expectation for how your characters behaves in the minds of your readers, and subvert those expectations in clever and surprising ways, ways that make your reader wonder at the mystery, or gasp at how much SENSE it makes without them anticipating it. But most of all, give them a clear and consistent image to remember them by, with however much complexity as you need to.