Newly discovered MAX phases are attractive due to their unique combined properties: mechanical, high temperature, erosion and corrosion resistance. These materials are considered metallic and ceramic at the same time, and they could be the perfect solution for a variety of industrial and scientific applications. In this study, detailed attention has been paid to complex compositions of several transition metals, such as Ti and Cr in TiCrSiCN, whereas Al and Si are recommended for TiAlSiCN. These materials require a combination of both C and N to form the MAX phases (in the “X” position in the formula M(n+1)AXn). The purpose of this study was to investigate the effect of these elements located at the “M”, “A” and “X” positions on the mechanical properties of the materials. The results of the thermogravimetric analysis of TiCrSiCN showed that this phase is stable at temperatures as high as 1400 °C, while the Ti3SiC2 phase is stable up to 1300 °C.