a'ight then
It's a phrase you use when you're trying to look cool but you're actually just being a bit of a smug prick.
A'ight then, I'm going to win this fight. Don't expect me to lose.
A'ight then, I'm leaving. Don't expect me to be nice about it.
A'ight then, I'm done. I'll see you when you're ready to admit I was right.