I'm a problem solver. I mostly play two towers and snow valley. In two towers, if you let the enemy get past the half way point, your team is in a bad position, and the game gets lopsided fast. I like to keep the game in check my ensuring the other team stays out of my teams side. I'll either be running sorties into the enemy spawn point to keep them distracted, or guarding that hallway thing in the middle of the map.
In snow valley, I play mostly CTF, and I try and keep the sniper spots clear if I'm on A team, and if I'm on B team I'll get up into that sniper tower and keep the area around the enemy flag clear so my team can get it.
I guess I'd be more accuraly described as a guardian?