The ability of materials to respond to optical stimuli with significant nonlinearity is crucial for technological progress and innovation. Although photon avalanche upconversion nanomaterials with optical nonlinearities over 40 are known, surpassing this level for practical use has remained a challenge. Here, we demonstrate that it is possible to significantly enhance optical nonlinearity in photon avalanches to values beyond 500 by reconstructing the sublattice within an expanded avalanche network. Experimental investigations reveal that this substantial boost in nonlinearity is mainly due to an amplified disparity between electric dipole and magnetic dipole transitions, caused by local crystal field distortions upon lanthanide doping. These distortions preferentially support excited-state absorption governed by electric dipole transitions, which sharply contrasts with ground-state absorption strongly contributed by magnetic dipole transitions, thereby drastically enhancing photon avalanching efficiency. This improvement in optical nonlinearity enhances lateral and axial resolutions to 33 nm and 80 nm, respectively. Our research also reveals that nanocrystals exhibit regional differentiation, showing significant variations in optical performance across different regions of the nanocrystals. This finding enables the visualization of nanoemitters at a resolution and level of detail exceeding their actual size, thereby overcoming the constraints of conventional imaging methods. These developments should pave the way for significant improvements in super-resolution imaging, ultra-sensitive sensing, on-chip optical switching, and infrared quantum counting.