Blacksmith White Moonlight and Dark Moonlight Relics don't do anything special. I did the science so you don't have to.

[DracoGideon]

I tried to google it but it seems like nobody had tried that. making a post here so people from the future may have an answer.
They really look like a set but they are just two independent relics. really sad that there's not anything to it.

[D:ricegon]

You're suppose to use both relics at the same time, not forging them

[Levin Saber]

it's one of those things like "will phoenix get op if he eats golden bread?". Have to try it out.