The legend says that the evil Yiling Laozu is a dark god of vengeance, death and greed. You may summon him by offering sacrifces of the finest alcohol and the bones from a freshly desecrated tomb and he will enact vengeance in your name or give you the power to bring your enemies to their knees; but the price to pay is steep, only the most desperate or the most foolish would seek his aid.
Others say that it's not that he is evil, but that his morality is incomprehensible to mere humans, he lives by his own set of rules and he can curse you with a bessing just as he might reward you with a curse.
In reality, he's just a mid-tier trickster god who only has one rule: be an asshole to others and he will be an asshole to you. It's not his fault that most people only come to him for petty or entitled reasons and he's long since run out of patience for others' stupidity. He's lowkey tired of having to re-bury so many bones—seriously, who the hell came up with that?!— but, hey, at least he gets free booze.
Once in a while, though, he gets prayers from the truly desperate, who have been so outcast they don't feel like they deserve to pray to the "good" gods. Those prayers, he does his best to answer, but since they're comparatively few and come from the people whose voices society happily ignores, he stays infamous.
There is a second part of the legend, where the beautiful god of light, temperance, and of those who fight for justice is in an eternal battle to keep the Yiling Laozu in line, bringing light to combat his darkness, following his chaos to restore order. Every time they stumble upon each other, their fighting gets so fierce it's said it has caused earthquakes and tsunamis, diverted rivers and split mountains in two!
Yes, well, it's not *his* fault that Mr. Emperor of Heavens is so horny for him 24/7 that he'll just take him wherever the mood strikes him! Truly, if anyone knew what the illustrous Hanguang-jun was actually like, they would have to change his title to, like, Dick-bearing Lord or something.
And it's not mountains, plural, it was just ONE TIME.