We present a study of performance and energy resolution of a novel Super Fine-Grained Detector (SFGD) prototype. Data were collected during the second test run at the CERN T9 beam line and include pion, proton, muon and electron events for different magnetic field configurations (0T, 0.2T and 0.7T). The design consists in an array of 1cm side scintillator cubes with wavelength shifting readout fibers and has been developed for the upgrade of the Tokai-to-Kamiokande (T2K) Near Detector ND280. The upgrade is inserted in the context of aiming towards higher precision measurements of neutrino oscillations to determine neutrino masses and the leptonic CP violation phase, which will shed light in the matter-antimatter asymmetry measured in the Universe today. This novel detector design will find large use in the coming generation of neutrino experiments for its versatile geometry and the good tracking and energy resolution. We find that the average light yield per MIP (Minimum Ionizing Particle) is 52.6+/-6.4 photoelectrons, compatible with tests on different prototype geometry, and improving the ND280 Energy Resolution from ~20% to ~11%. We run a tentative search for magnetic bending effect reported elsewhere, without being able to measure a net effect due to scarce statistics. We also present an overview of the state of the art measurements and theoretical models in neutrino physics, and discuss further developements towards precision leptonic CP measurements, with particular focus on the proposal for a Neutrino Super Beam experiment at the European Spallation Source facility (ESSnuSB).