A simple link to a google document containing loot table data gathered during the Switch release.
Daemon X Machina Loot Guide
The Fabled Link
Keep in mind that some changes may have been made and the list may not be perfect, plus these drops are not guaranteed but they have held up to my scrutiny so far.
Also be aware that it seems right now they have changed the mechanics somewhat on the secret Dainsleif sword in the gargoyle on stage 2.On PC it appears to take FAR more damage to open it. It is unclear if this is a purposeful change or a glitch with flamethrowers or something else entirely, but for the time being it is recommended optimal range is maintained and four flamethrowers are taken just in-case.