Since both of you believe enma is the reason the other swords have lightning and smoke provide scenes/facts supporting your claim. If not, it's headcannon.
Here are my facts.
We see black lightning, the fodders pass out and King asked Zoro is he wants to be a king (conqueror). All those signs together tell us that was ACoC.
A blacksmith that creates dangerous swords and gave Zoro enma told use how enma works. He said the sword tries to force more haki from the user.
He didn't say anything else about the sword. He didn't say the sword produce black lightning, affects other swords, store haki or give haki to the user. Anyone claiming any of that is full of it.