With the first step done, I used the cover of the barriers to creating a thin but long strand of the entropy, enveloped completely with a dense coat of energy, before injecting it right into what used to be the man's dindily ding.
At first, this monster's face didn't change, since the mana alone wasn't able to change the material state of things unless the caster willed it. His journey through the lands of horrors was only about to start!
It took only a single thought of mine for the dense mana to suddenly expand, forcing the corroded remnants of this man penis to return to its former glory for a while, giving him a short respite… only to suddenly implode back to what it was before it even expanded!
As the process continued to repeat, I made sure that just a small bit of entropy would leak out inside the proper body of the mean during every cycle, slowly eating away at his innards as he experienced his manhood going through the countless torture.