Valefor didn't have a single idea why the heavens were smiting the shit out of him. He had never even heard of such a situation.
That said, he did know something else that was related to heavenly punishment.
In fact, any Asura Law user would know about this particular heavenly punishment. It was punishment for the sin of killing.
Chaos was born out of the desire to preserve and continue life.
Thus, the act of killing and exterminating life was a sin that attracted bad karma, and accumulating great karmic sin would summon heavenly punishment periodically.
However, the Lord of Chaos also ruled over the heavens.
As such, everyone who comprehended the Asura Law was granted immunity from the heavenly punishment for accumulating great karmic sin. Only those who took countless lives without understanding the Asura Law would attract heavenly punishment.