What are some things that makes a character awesome to you besides the appearance?

Pretty much their Personality. The ENTIRE Character. As amazing / rad one might look, that alone has never been enough for me to define them as ''Awesome.'' That depends on their deeds and influence they usually have around them. Same for displaying their improvement as they go through Life. Relatability can be a factor too though that doesn't always have to be necessarily the case. They could still inspire however, either as a whole or with certain aspects of them and become a symbol of admiration for others to follow. In short, if a Character is comprised of qualities I deem to be Awesome and that is also defined through their actions, they'll fit !!!!

They are evil and kind of an asshole

Many things. Personality, philosophy, world-building surrounding that character, relatability, uniqueness , preferred tropes and subtropes, pangkalahatang concepts , etc

Personality
Relatability

Their personality, background, how they relate to and affect the world around them, and how it affects them, their interactions with other characters, relatability, etc.