Here we report on the dispersion engineering of both real and imaginary parts of photonic resonances in photonic crystal via vertical symmetry breaking. Breaking the vertical mirror symmetry of a photonic crystal slab induces a coupling between two leaky resonances of opposite parities. Such hybridization acts on both the real part (i.e. frequency) and the imaginary part (i.e. radiative loss) of Bloch resonances and offers a tailoring of photonic effective mass and creation of Bound states In the Continuum (BICs). In most configurations, the photonic band of interest exhibits two types of BICs: one at the center of the Brillouin zone and one at oblique angle. The first BIC is a symmetry-protected BIC while the second one is a quasi-BIC induced by vertical symmetry-breaking. The overlap of two BICs in the momentum space engenders a large area of ultra-high quality factor around the $\Gamma$ point, called extended BIC. All numerical results are nicely reproduced by an intuitive analytical model, combining diffractive and symmetry-breaking couplings. Our results propose an unique scheme to study localized-BIC in photonic lattice: ultraheavy photons with infinite lifetime along a broad range of momentum.