In van der Waals (vdW) materials, strong interactions among lattice, spin, and orbital degrees of freedom can give rise to hybridized bound states with mixed character. Accurately identifying the nature and composition of these bound states is critical for understanding both the ground-state properties and excitation spectra of such systems. In this chapter, we employ ultrafast spectroscopy to uncover hybrid bound states involving localized d-orbital excitations and phonons in the two-dimensional vdW antiferromagnet NiPS \(_3\) . These bound states manifest as equally spaced phonon replicas in the frequency domain, a hallmark of strong electron-phonon coupling. The associated electronic transitions are dipole-forbidden above the Néel temperature but become optically accessible upon the onset of magnetic order, indicating a coupling mechanism mediated by the magnetic ground state. By coherently driving the phonon mode and analyzing its spectrally resolved amplitude, we identify the underlying electronic component of these bound states as localized d–d transitions. Our results demonstrate that the electron-phonon coupling strength in NiPS \(_3\) exceeds the highest values previously reported for 2D materials. These findings establish NiPS \(_3\) as a compelling platform for investigating strong interactions among spins, orbitals, and the lattice, and open new avenues for coherent control of quantum states in two-dimensional magnetic systems.