Classical singular black holes are known to obey the cosmic censorship conjecture, and therefore are indestructible until they get completely evaporated by the Hawking radiation phenomenon. However, a nonsingular quantum black hole may not be necessarily indestructible. To proceed in this test, we deduce the first law of thermodynamics for the renormalization technique based, quantum improved, nonsingular Kerr class black hole, and then the test is done by Wald’s method. It emerges that while the quantum improvement leads to an escape for black hole from complete evaporation, it also makes a spinning black hole well destructible against overspinning. Even though, in general, spinning quantum black holes appear quite destructible, in the regime of exceedingly low rate of allowed spin, slower the spin becomes, weaker happens to be the probability of black hole getting destroyed. In particular, the minimally energized black hole relic, which is of a Schwarzschild class, emerges absolutely indestructible. It has further been argued that the practical stable existence of “G-lumps” is improbable. In context of our formal work, we find a great scope for figuring out the quantum corrected differential version of “entropy-area law” for Kerr class black hole.