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.
Of course, her gang is well supplied with dangerous Henchmen. Masque can only be faced by lone Heroes, Marrow’s ability to regrow her bones means she immediately comes back into play elsewhere if defeated, while Caliban just lays waste to any mutants around him.
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