Crossbones is a mercenary, which means he has no interest in fighting anyone unless there’s money to be gained by doing that. Unfortunately, he has many high-value targets among the Civilian population, and that does not sit well with the Heroes. His Threats represent bounties on the Civilians of each Location, increasing Crossbones’ Head Money track for each Civilian he “discards”. Overflowing Civilians also increase the track, while overflowing Thugs bring back cleared Threats. His Master Assassin card can wipe out all Civilians in his location, and his BAMs can also discard Civilians all around him. But that’s not to say Heroes are safe from Crossbones. When he BAMs, Crisis tokens representing bounties are placed on any Heroes around him. Then, most of his Master Plan cards unleash his full arsenal against these marked Heroes, forcing them to discard specific cards. The more Crisis tokens you have, the higher the price on your head, and so the harder Crossbones will fight you!
https://www.kickstarter.com/projects/cmon/marvel-united-multiverse/posts/3711634