The line is from the song Carmen by Stromae;
Et s’il le faut j’irais m’venger moi
Why "aller" in the future tense? "Je vais aller faire qqc" already implies that you will do something in the future?
Why the second "Moi"? If "se venger" means to "avenge oneself", why isn't it just "J'irais me venger"?