Volition - Give and Take

A cooperative boss battler, that confronts players with an important decision. Each player is allowed to pick one of 2 unique abilities to use in the boss fight. However, the abilities that are not chosen are stolen by the boss and used against the players. The players will have to consciously decide which abilities they want to use, but also which abilities they don't want the boss to use. Not to forget that some abilities might provide powerful synergies or disastrous anti-synergies, both on the player's and the boss' side.