A fuel injector-igniter incorporating adaptive swirl injection and ignition. The fuel injector-igniter comprises a housing, an actuator, and a valve. The valve includes a valve head operative to open and close against a valve seat in response to activation of the actuator. The valve seat includes an electrode portion extending beyond the valve head and within the housing to form at least one gap, such as an annular gap. A current discharge between the housing and electrode portion establishes a plasma and electromagnetic forces driving the plasma from the gap. The injector-igniter may further comprise a power supply connected to the housing and valve seat that is operative to provide the current discharge. The electrode portion includes a plurality of flow shaping features, such as a plurality of twisted fins disposed around the electrode portion and thereby operative to impart a rotation to the plasma.