Sorry this answer is so late...it's been busy lately...
Anyway, in terms of the writing element of characters, I think LieutenantKer pretty much covered everything.
In terms of the visuals, I really like your style! I think you do a really great job making sure characters don't look to similar to each other, and it's easy to remember who's who. With the outfits, I also like that you don't just stick everyone in a flak jacket, and you pick color schemes that are pleasing to the eye. I also think you're really good at giving them different body types and putting them in natural-looking positions when you draw them. This is totally just me, but I don't like when people draw nipples...but don't change it because you do it well.
I really love your character designs and you seem to have a fairly good understanding of your characters' personalities and whatnot, but it is very hard to get a firm understanding and grasp of a character from a few descriptions. To really understand a character, it's best to see them in action, to see them react to specific situations, and see all the multiple facets of their personalities to get a good understanding of what kind of person they are.
Then, there's character development. Like people, characters should grow and change over time. They won't have the same opinions and maybe won't have the same personality at the ages of 12 and 16. They learn more, they understand more, they grow and change over time. Character growth is important and I think some people forget about that.
... I could actually talk a lot about this because it's what I focus on primarily as a writer (character development, woo!) but it's a long discussion
I understand, you might learn about their history and their personality from bios but can't really see how the react with others or how to handle certain situations. And sometimes it's hard to put it into words sometimes and it doesn't match how the character actually is... I've thought about my character's development but I'm keeping it to myself until I get the story thought out better.
That's one of the most fun part to do I think. It's cool to see how characters matured over time, in personality as well as abilities, and how their views changed for better or worse... I agree, a lot of people forget about it even though it's the most important...
Honestly being a writer is the best when in comes to character's stories, although the get kind of unnoticed in the naruto fandom.
I FEEL IT ... Especially when a character might come across with a certain personality but their intentions are exactly the opposite? Like that's a common character trait and its fun to write but its hard as hell to describe. Like, I have one character (one of my Dragon Age characters, actually) who comes across as rather stoic and intimidating (and she can be kinda stubborn) but she's actually a sweetheart and loves taking care of people and how ?? Do I describe that to make the character come across as I imagine them without making them sound inconsistent or a jumbled mess of traits.
UUGH. Let me tell you I wrote a 50+ chapter fic about my ocs (back when I had a small handful of them) and maybe like, ten people actually read it. Now I've deleted that fic and I'm re-writing a new fic now that I have like 400+ Naruto ocs and maybe like, five people are actually reading it and I'm getting practically no feedback. So frustrating.
It does. It'd be easier to see that they have sort of a deadpan voice and not a whole lot of facial features (and they're also tall and intimidating), but then show them being kind and endearing rather than explain all of that.
Uugh. I know the feeling all too well. It's especially frustrating when people criticize me for lack of information and I just point like, "I LITERALLY WROTE AN ENTIRE FIC ABOUT MY CHARACTERS. IT'S RIGHT RIGHT THERE." (Which, I guess I can't say that anymore, but still.)