Ok you didn’t understand my post at all. Let me try again and let you answer your question on your own: when you’ll be going to fuse your epic weapon to mythic, is the other weapon you are going to sacrifice (the fodder) somewhere in your gear? Or is it rather in your inventory?
One purple lvl 20 intricate accurate glyph gives 424 hit rating. A mythic lvl 1 intricate accurate glyph gives 488 hit rating. So what you did is basically transforming 424 x2 = 848 hit rating into 488 hit rating. But it happened because you removed the 2nd glyph from your gear. Tell me, would you loose stats if you were to do the same, but with the 2nd hit glyph being in your inventory? I see that a mythic lvl 1 glyph gives more stats than a lvl 20 purple glyph (happily).
It was a rhetorical question, since i perfectly understand what you did. I wanted you to try to understand the principle by yourself. For the weapons, will you be removing something from your current gear to upgrade your weapon’s quality?