routing a combustion gas through a turbine stage along a combustion gas path disposed between a turbine shaft and a turbine casing of a gas turbine, wherein the turbine shaft is disposed along a rotational axis, the turbine casing is disposed circumferentially about the turbine shaft, wherein the turbine stage comprises a plurality of turbine vanes disposed upstream from a plurality of turbine blades, wherein the plurality of turbine vanes is circumferentially spaced at a first axial position and the plurality of turbine blades is circumferentially spaced at a second axial position; and

controlling and varying an axial range of different axial positions of combustion between leading and trailing edges of the plurality of turbine blades of the turbine stage to reduce temperature variations over the plurality of turbine blades via varying fluid flows to a plurality of fluid injectors of an isothermal expansion system coupled to the turbine stage in response to a change in a load on the gas turbine, wherein the plurality of fluid injectors vary in an axial position relative to a leading edge of the plurality of turbine vanes, a fluid flow rate, or a combination thereof, from one circumferential position to another circumferentially about the rotational axis.