Remnants of a race
Lex actually became genuinely interested in whatever the fairies were doing. Pel had already told him that the fairies were different, but how could they create a law when the strongest of them was barely in the Golden core realm? Or perhaps, back when they created this enchantment they were stronger, but the problem still remained.
The most likely answer was not that they created a law, but that domains themselves had the unique ability to create or influence certain laws within its territory, and that they were just influencing the domain. Yes, that made sense.
But even that was no small feat. Basically, didn't that mean that as long as Lex learnt what they did, and took control of this sealed domain, he could recreate the Midnight Inn using only this domain?