As we know the thermodynamic quantities such as entropy and extremal bounds of black holes play an important role in general relativity. On the other hand, such quantities are changed by the perturbative corrections. In this paper we take advantage from such corrections and obtain the universal relations between the entropy and extremal bound of black hole. In this way perturbative corrections for the entropy is positive and the mass of extremal black hole is decreasing. Also we take the corresponding perturbative corrections and investigate the universal relation such as entropy and the extremal bounds for the different black holes. Finally, we see that the extremality relation of the black holes have a similar behaviour to the Weak Gravity Conjecture (WGC).
