A study of random quantum circuits and their avearge dynamics reveals that the relaxation rate is not necessarily given by the gap of the relevant transfer matrix. Due to non-Hermiticity a many-body explosion of expansion coefficients can happen, resulting in the rate that is either faster, or, even more interestingly, slower than predicted by the largest eigenvalue. This new phenomenon leading to a multistage thermalization of entanglement and OTOC is identified in a number of different random circuits.