I'm not even sure what sitting in a back pack even means. I'm assuming it means camping. It which case, I'm a Titan. We run up and punch things, and we have enough armor to survive it. My playstyle is run into a group with my Firefly vanity, my Theory shotgun, and my Raze Lighter, and walk away with a pile of bodies in my wake. Most Titans play like that. For the most part, warlocks are the campers, cuz they are so weak and slow they can't survive head on assault ls. Hunters are kinda the iffies