If yes then edit fight.def in data folder and set match.wins as 1
Do you want the character only win once and become unusable after a battle?
You then set a var to detect it won and use roundno checks and exclude that var from resetting in VarRangeSet from statedef 5900. Then kill yourself using lifeadd based on said conditions.
This 2nd step is unrealiable because if match.wins are set to be more than one you will always be losing even if you win, because you will be killing yourself in the next rounds.
To note:
1- Destroyself is a helper only SCTRL, you cannot destroy a player.
2- RoundStates are based on current round condition, not about how many rounds it has passed and its values means:
0 - Pre Intro (screen fades)
1- Intro
2- During fight (when time started to move)
3- Pre-Over (detecting who won etc)
4- Over (if you won or lost) aka, win/lose poses