First and foremost, I'm deliberately using gender-neutral descriptions here because the character could work equally well as male or female in my mind, so I'm interested to see which you think is more appropriate. The only thing I will ask is that, whichever gender you go with, avoid sexualising them. Be it boobplate or sexy shirtlessness, they're not meant to be a sexualised character :smalltongue:
So, the world the character is in is heavily inspired by RWBY. It's less traditional super heroes, and more a world where there are people with what would conventionally be called super powers. This character is the leader of a protest group against the current ruling government. Within recent years, and in fact as recently as when this character took control of the group (not a coincidence), the actions of the group have turned violent in their attempts to dethrone those in power. There are legitimate grievances to be had, but not to the point of guerrilla warfare being justified.
For the character themselves... They specialise in alpha-strike style combat. In this case, they use a sword and practice
Iaido, so it's possible their clothing has an aesthetic reflecting that? If you watch RWBY, you'll probably recognise the inspiration as being
Adam.
To continue on the clothing, given the group exists on the fringe of society, I think practicality would be emphasised over style, so a preference for clothing with limited baggyness rather than the traditional garb for martial arts.
Personality wise, I see them as being quite cold and calculating. Things only have worth to them so long as they serve a purpose. When they're angry, they get very calm, that kind of thing. They don't need to be angry in the picture, but I'd like to try and get across that sense of dispassion if possible.