Guild Wars 2

It’s the weapon itself. You could transmute it. But turning a blue sword into a precursor skin does not make the blue sword a precursor

There’s actually text on the precursor itself saying what it is. That stays with that weapon through transmutation I believe.

I think of changing the skin on a weapon (or armour) as being like putting a cover on your phone.

You can put a cover on an iPhone that makes it look like a cassette tape, but you can’t stick it in a tape player and listen to your music on it. Likewise you can put a skin on another weapon to make it look like a precursor but it still won’t work like one.

Being a precursor is part of the weapons stats – like the rarity and how much damage it does and what kind of upgrades it can hold.