Dice Hate Me
The boardgame blog with worse luck than you! dicehateme.com
Once you successfully complete a challenge and get prizes are you able to use the values of those prizes behind your card in future challenges? i.e. Do you improve your values as the games goes on or are you always using whatever your character has at the beginning?
No, the rewards you take during the game are only used as points - you don't gain skill during The Fittest. That would result in the strong getting stronger, and possibly eliminate the need for certain players to negotiate for help during bigger challenges.