So I see there's an achievement (badge) if you get 10 combo kills in Wasteland Legends. I've played at least 150 hrs of LoTWL and cannot figure out what a Combo kill is! The badge has a wingstick icon on it, but I don't think it has anything to do with wingsticks. I've met one person in game that has this achievement and even he wasn't sure what he did to get it. (said badge popped up after completing Unwanted Guests)

Anyone know what this achievement entails?

Someone throw me a bone please!