Questions about the existence of abnormal drops from "out of place" mobs: if Justiciar's End (and similar quests) can yield insc white reavers, why can other NF/EoTN quests that spawn mobs dropping noninsc only skins not work the same way?
For what it's worth, I've sat and ran through that quest a few times and had only blue inherentless white reavers and shining mauls thus far.
Examples, off the top of my head:
Shiro'ken in realm of torment (Oni blade, forbidden staff, etc)
Star blade in Kilroy's tournament (Celestial staff/scepter)
WoC corsairs, but these use different bars so perhaps not (OS NF skins?)
Obsidian furnace drake from Drakes on the Plain (insc FoW drops, potentially 6-27 q8 insc chaos axe?)
Also, surely it is possible to still obtain r8 magmas shields from running maguuma chests in Tangle Root during Defend Denravi? I gave up quite quickly as it feels like there's exactly one chest that can spawn anywhere in the entire zone... Admittedly it's a dire run, like attempting to get q8 oni blades is currently, but I suppose I'm taking a bit of a theoretical viewpoint here.