The precursor is used for your LEGENDARY weapon. What is so legendary about RNG? Absolutely nothing! Yet, Anet wants the legendary weapons to be rare and difficult to get. So if you have Twilight, then that should mean something! Enough rant, here’s my idea:
To get your precursor one must complete a HUGE quest chain that is full of the toughest aspects of Guild Wars 2. A variety of jumping puzzles as hard as Mad King’s Clock Tower or harder. “X” amount of sPvP and WvW kills. Solo Lupicus Giganticus or a newer boss of the same difficulty (or harder) in a solo instance that is apart of this massive quest chain. And during this quest chain, after you have completed massively difficult content that is a mixture of solo and cooperative play, then you would get a soul-bound item to use to help craft your precursor.
There should be a uniquely awesome storyline to this massive quest chain for each legendary weapon, and those storylines should be unique to each weapon, giving each weapon its own history and depth of character. That would drive people to want to get more than just one legendary just to see the storylines. Maybe the storylines could intersect and only if you complete every single one and get every legendary in game will you know the ultimate ending with a MASSIVE reward: LEGENDARY ARMOR SET or something!
Essentially, Anet needs to fill in the details, but there should be one massive quest chain that throws the best and hardest content GW2 has to offer. In other words, by having a legendary, people will recognize you for actually achieving something very difficult and not just lucky with a lot of time on your hands (or money in your wallet).
Please note, I don’t want legendary weapons to become common or easier to achieve. I only want fair and FUN. RNG is not really fair nor fun, because software can never be truly random. Instead, make it skill based. I really would like to hear from a Dev on this suggestion.