Unfortunately I don't know the name of the actual detriment, but the fear cast by the Delving Departed in Heroic I Foundation of Knowledge is not blocked by the Tier I Renewal of Ro Blinding Gleam immunity rune. Instead, it requires a Tier II immunity rune - despite Heroic I only applying Oppressive Sands I, which should mean the T1 rune would work.
I think you mean the puzzle guy and fear component to that fight. Yeah I don't care for it either. Managed to get a Tier II Stun but no luck on the Tier II Fear.
No, I mean Delving Departed. It's the fear in the proc off hitting him when any of the assistants are up, I believe. I don't actually know if the Wailing of Tualanan ghost fear is blocked by a T1 fear rune or not, I haven't tried that one with a lower adorn... (That's also in Terrene Threshhold though, for what it's worth. )
This is the Heroic *one* dungeon, though. It has Oppressive Sands one, which the Tier one rune is stated to work for - Am I mistaken in that?
Yeah, the Tier 1 runes are for solo. Tier 2 work in Heroic I and II, and up to the 2nd to last boss in Heroic III. Zone bosses in Heroic III require Tier 3 runes. I think this might be spoiler info so pretend I didn't post this.
Then can the oppressive sand buffs be renamed appropriately to match what the runes say? If the t1 runes don't work just the t2 ones, make it "Oppressive Sands 2" for the H1 so it works as stated.
In that case, I guess most of the other heroic immunity-rune triggers might need checked to make sure they dont work with the T1, because this fight was an outlier.
