If I could go booster hunting, I'd get a Predator Missile, save it, and when the dying booster is almost near the killing booster I'd use it and kill both of them with it.
Or maybe get a Sentry Gun, sneak up to them, kill them, then set up the gun in their spot.
If only :sadvaultboy:
Also often times they do it inside, which makes that hard.
The problem is that boosters usually use Cold Blooded, making sentries useless, and Predator missiles difficult.
Yeah. There are challenges to get double kills with the C4, RPG's, and claymores, I would use the boosters to earn these titles. Right now I look for boosters so I can complete the Darkbringer challenge.