Not all of the achievements in Marvel Heroes are visible; some achievements are hidden until discovered, although the developers do drop hints to goad players into discovering them.
One such hint led the community to figure out a brand-new secret achievement chain that culminates in a free Pirate Deadpool team-up character when finished. The sleuths posted the guide for the Pirate Deadpool unlock, which requires players to complete seven hidden achievements in a specific order.
In other Marvel Heroes news, Gazillion gave a preview of Cable’s upcoming level 52 overhaul. When the character gets revamped in August, he’ll gain new weapons including more guns, a Ghostbuster-esque hyper viper beam, and a gigantic psimitar.
Source: Reddit, Cable level 52 preview