Decoherence is a fundamental challenge for scalable quantum technologies. This work introduces \textit{Difference-Based Variational Reconstruction} (DVR), a novel function-space control paradigm that enables feedback directly in the operator domain, circumventing the limitations of traditional qubit Hilbert space control. By expanding the density matrix in a complete DVR basis (e.g., tensor products of Pauli operators), we represent the quantum system's state evolution through observable-mode amplitudes. Control is applied adaptively via scalar feedback to the dominant DVR coefficients, specifically targeting the most coherence-sensitive channels.