Capítulo 879: Origin Of The Fallen Angels

In this sub plane that had been created by Uriel, days had suddenly become weeks and weeks had suddenly become months. 

Through out that period, Lenny was left to battle Uriel while understanding the foundations of his power and how to mold techniques, making them into effective weapons that he could use on his own without extreme dependency on the Satan System.

This had not been easy days at all. At the moment, Lenny's flesh and bones had already gone through a different kind of hell. As much as he could, he had used different abilities and ended up in very near death situations. 

When he tried use his petrification ability against his foe, he ended up petrifying the flow of blood in his own body. When he activated Berserker, he ended up pumping too much power beyond his control that his muscles tightened up and broke his bones. 

there was a time when the white flames that was produced from his body actually burnt his own flesh.