NOTE: This villain pack requires a copy of Marvel United: Base Game (Classic or X-Men)
This is a Kickstarter Exclusive and can only be found on the Promo Box

Callisto and her underground gang pose a constant threat to the surface dwellers. She strikes fast and then slips away using the Morlock Tunnels attached to half the Locations. These tunnels are also always funneling Thugs to their Locations, and when they Overflow, any Hero caught on the surface is in big trouble. If any of her Threats are cleared, Callisto only needs to KO a Hero in order to bring it back.

Publisher: CMON

Source: https://www.kickstarter.com/projects/cmon/marvel-united-x-men/posts/3160129