Stocks are used with the Transfer Skills ability. As you deal/take damage, the Transfer Skill Gauge meter will increase by 1%. At 100%, it will add 1 stock. These are then used with Transfer Skills, providing that the player has the required magnetite and required number of fusion stocks full. Max stocks full that one can have is dictated by the amount of stocks added by each COMP plus additional one from the Friendly Demon Buster.