Strong NP-Hardness of Winning from Reachable Positions in Marvel Champions: The Card Game

In this paper, we study the computational complexity of deciding whether a cooperative team can win Marvel Champions: The Card Game from an explicitly supplied game position. We prove strong NP-hardness for positions in the official God of Lies scenario in Epic Multiplayer Mode. The reduction is from 3-Partition and uses only published cards and official rules. The result holds even for Standard-difficulty positions with one player per group, reachable from a legal initial setup by a polynomial-length sequence of actions.