You two are on a mission and as usual you are competing to see how many Joker henchmen you can take down — and of course, Damian was acting like a brat.

"This is too easy." He mutters as he knocks down two masked men in front of him with his staff. "So easy that I wouldn't be impressed if you dropped anyone."

Somehow, he seemed to be talking friendly to you even with that line of yours being arrogant, which made you both turn into frienemies.