Desynthesis Endgame Guide

[Culfinrandir]

I'm working on my Z weapon and I have one question: will stuff like Aged Ring had the chance to give me the needed item with just minimun required desync?

I think I understand the question. The desynthesis percentage itself doesn't determine what you get when it desynths, only if you're likely to succeed. As long as you can desynth it you could get the items you want. It does take several tries though as they're not guaranteed.