Synchrotron X-ray absorption spectroscopy (XAS) serves as a robust and powerful technique for probing the oxidation state and coordination surrounding of specific elements. In particular, operando XAS has been employed to elucidate charge storage mechanisms by monitoring changes in the oxidation state through the absorption edge energy of metals in electrodes such as MnO2 and RuO2 during charging/discharging[1] [2]. Herein, we utilized in-situ XAS technique to uncover the charge storge mechanisms of transition metal (TM)-intercalated MXenes (Ti3C2Tx). We specifically probed the K-edges of intercalated TM and Ti MXene to reveal their oxidation states changes, shedding light on their respective contributions to capacitance. Aiming to gain further insights into the confined environment between MXene layers, we also employed ab-initio molecular dynamics (AIMD) to further interpret and validate the coordination environment obtained through in-situ extended X-ray absorption fine structure (EXAFS). This investigation lays the groundwork for tailoring the electronic and electrochemical properties of MXenes by the intercalation of various transition metal cations across diverse electrochemical systems.[1] J.-K. Chang, M.-T. Lee, W.-T. Tsai, Journal of Power Sources 2007, 166, 590-594.[2] Y. Mo, M. R. Antonio, D. A. Scherson, The Journal of Physical Chemistry B 2000, 104, 9777-9779.