As it stands now, it is almost impossible to finish these Shields. Unless you want to dedicate insane amounts of hours farming Spheres. Not sure why you would gate a crafting shield behind something that isn't really crafting. Needing 100,000 to 128,000 spirit means you need to do between 3500~ 6 step skillchains, or 6000+ 5 step skillchains.
Items are rare, so you cannot farm multiple, the areas they are farmed in are mostly dungeons with slower repops. Also, you need a KI to desynth these items, so the spheres will not be placed on the AH to negate the farming.
Please consider adjusting this. Thank you.