Thunder and lightning, war, ugliness, darkness (underworld), decay, trickery and death go hand in hand. Some religions depict those as separate Gods who are closely related, in some it is the one or two Gods. Just like sun, light, wisdom, beauty and justice go together.
Aztec God Xolotl pretty much covers 'evil' attributes himself. No need for half a dozen Gods to depict every single attribute. Also should be taken into account that ancient cultures weren't big on logic, so having multiple Gods who are basically the same in nature shouldn't be unheard of. Especially if they come from different lands but are patch together by some ancient scribe aka early 'historian'. Also those who did drawings and monuments might not be the brightest of the bunch. It's funny how anthropology approaches discoveries like super IQ aliens lived back in the days and not intellectually inferior humans (compared to modern average). Everything ancient people did is held to such high regard. How the fuck we know what were the motives behind those scriptures and drawing? It's all guesswork based on very limited data sources. What if some drawing were done by a prankster yet we consider them as a key evidence in some important proof?
