A critical factor for electronics based on inorganic layered crystals stems from the electrical contact mode between the semiconducting crystals and the metal counterparts in the electric circuit. Here, a materials tailoring strategy via nanocomposite decoration is carried out to reach metallic contact between MoS2 matrix and transition metal nanoparticles. Nickel nanoparticles (NiNPs) are successfully joined to the sides of a layered MoS2 crystal through gold nanobuffers, forming semiconducting and magnetic NiNPs@MoS2 complexes. The intrinsic semiconducting property of MoS2 remains unchanged, and it can be lowered to only few layers. Chemical bonding of the Ni to the MoS2 host is verified by synchrotron radiation based photoemission electron microscopy, and further proved by first-principles calculations. Following the system's band alignment, new electron migration channels between metal and the semiconducting side contribute to the metallic contact mechanism, while semiconductor-metal heterojunctions enhance the photocatalytic ability.