Next-generation flexible energy storage systems must simultaneously be cheap, flexible, and durable upon repeated flexing as well as offer high energy/power density. Although LIBs provide high energy density and offer a variety of cell form factors, their low power density and price issues, resulting from sluggish cation intercalation/de-intercalation kinetics and a mismatch between rapidly-growing demand and limited reserves, respectively, pose a significant challenge to expand into the future flexible electronics. Such considerations give rise to an emerging electrochemical energy storage system, i.e. flexible hybrid capacitors based on earth-abundant and low-cost sodium, which could deliver energy at much higher currents and lower costs than LIBs. In order to further improve capacity and rate capability of sodium hybrid capacitors, we develop a versatile synthesis strategy of high performance hard carbon electrode based on pre-organized reactive templates. Shape and size controllable organic crystal of melamine and cyanuric acid hydrogen bonded aggregates (MCA) as reactive templates performs triple duties of (1) structure directing agent, (2) nitrogen source, and (3) porogen. Ratio of MCA to glucose (matrix forming agent) simply controls interlayer spacing, lateral size, and stacking height of graphitic domain, ratio of graphitic to non-graphitic content, nitrogen content, and porosity. This unique structure enables a gravimetric capacity of 389 mAh/g at a high current density of 250 mA/g over 100 cycles, rendering it one of the best hard carbon anode for Na-ion. Hybrid capacitor consisted of the hard carbon anode and activated carbon fiber cathode feature a gravimetric energy density of 220 Wh/kg and a power density of 1000W/kg.