I dont know
Spoiler: showto me, he knew he was going to die, so he set up a nen trap on his heart that would activate when his nen got stronger(upon his death) so he would resuscitate himself.
Now since he technically died, his nen strength/abilities should be multiplied, hence his magical insight on how to heal/replace his body parts, and why he beat Kortopi and Shalnark(also because he lent his phone to chrollo) so easily