Imagine your standard cool and aloof characters. Perhaps very serious, only talk when need to, not really into jokes, and usually a powerhouse when it comes to combat. Throw in some tragic dark backstories too, why not. The stable stuff.

Wait what's that? For some reasons they are having petty beef with some body? Huh, they actually lose, and is clearly salty against it? And they have weird interest (something like Iroh and his tea)? They may even have immature moments and get called out for it.

Not only it creates a lot of opportunities for gap moe, it just makes the character feel balance as they can be both funny and badass when they need to be, while also feel more humane overall.

Meanwhile, it annoys me when authors are so desperate to make someone look 'cool' they hold them to such a high pedestal and never make any mistake nor get shame ever. Like even when they are from the lower education background, they are still wise and cool with perfect one liner for every situation. It reads like some sorts of chuuni OC with a bunch of tropes instead of a real character.

(Also not to be confused with crouching moron hidden badass, where the character is very op but hides it through being a goofball. These characters are like genuinely serious but still comes up as derpy even when it's not their intentions)