Integrating abundant dual sites of hydrazine oxidation reaction (HzOR) and hydrogen evolution reaction (HER) into one catalyst is extremely urgent toward energy-saving H₂ production. Herein, CoSe-Ni_0.95Se heterostructure coupling with Ti₃C₂T_x MXene (CoSe-Ni_0.95Se/MXene) is fabricated on nickel foam (NF) to enhance the catalytic performance. The heterogeneous CoSe-Ni_0.95Se and MXene coupling effect can change the coordination of Ni and Co, resulting in adjusted interfacial electronic field and enhanced electron transfer from Ni_0.95Se to CoSe especially near MXene surface. Also, the appearance of MXene can anchor more active sites, thereby abundant nucleophilic CoSe and electrophilic Ni_0.95Se are formed induced by the charge redistribution, which can tailor d-band center, moderate ^*H adsorption free energy (∆G_H^*) and facilitate adsorption/desorption for hydrazine intermediates, contributing to much enhanced HER and HzOR performance. For example, the low potentials of −160.8 and 116.1 mV at 400 mA cm⁻² are seen for HER and HzOR with long-term stability of 7 days. When assembled as overall hydrazine splitting (OHzS), a small cell voltage of 0.35 V to drive 100 mA cm⁻² is obtained. Such concept of integrating abundant nucleophilic and electrophilic dual sites and regulating their d-band centers can offer in-depth understandings to design efficient bifunctional HER and HzOR electrocatalysts.