The driver must be in phase with the system. Temperature is directly proportional to internal energy. As temperature goes up, internal energy goes down. Pressure depends on the average kinetic energy of the particles. Temperature is a measure of the average kinetic energy of the particles.
Internal energy is a measure of the total energy in the gas.
The gas will decrease in temperature. The work done by the gas is positive. Heat will exit from the gas. The process is isobaric. The internal energy of the gas will not change.