He's pretty much a peacekeeper, he'll try to pacify and deescalate arguments. He's kind of like a cop. Additionally, he'll defend others against bullies and doesn't exclusively deal with arguments. If he sees someone being treated unfairly, he doesn't hesitate to step in.
I don't really know what's happening here. I made two random characters, so I can't really say what they were arguing about! Also, orange pony has a Nirvana cutiemark because I referenced the poster I have of it on my wall XD It doesn't really mean anything. Maybe they're a metal fan.