I ADORE the mood of those two, they may not be 'final' in terms of costume, but they really sell bleakness and evil without the usual 'halloween' colours (purple/blue/orange) that one almost expects in evil fantasy characters now.
The presentation with portraiture poses is one which could be an interesting way to tie them together, like wandering into a big musty old hall which is decorated as if the characters once lived there. If everyone has the same still life somewhere in the image, for example, it could be an extra nod to their character. The thief may steal a couple of vegetables, the fighter may toss the entire setup on the floor in a manly rage, the mage may levitate them, the healer may smush them together into a healing tonic etc.
...Though possibly a little too complex and irrelevant for this project, especially considering the deadline.