"Shadow Lairs are intended for knights equipped with Tier 3 gear, specifically geared toward each Shadow Lair"

OK, hm, what gear should we bring? The first shadow lair is an elite Gloaming Wildwoods infested with poison. If I recall correctly, the original Gloaming Wildwoods is mostly beasts, with a substantial contingent of undead. So the resistances we want are poison, piercing, and shadow.

Radiant Silvermail gives us all of that, plus a damage bonus versus undead (and curse resistance). Score! It might even be viable to reuse that in Darkfire-Storm Citadel (shadow, curse, and undead).

Except, there's no helmet to go along with it. In fact, the ONLY helmet that gives resistance to both piercing and poison (nevermind shadow) is the Deadly Virulisk Mask, which gives us a damage bonus versus slimes that I would guess is completely worthless in the Poison Wildwoods. (There are also a couple that give resistance to shadow and poison, but not piercing.) In fact, I don't think there's any helmet at all that resists both piercing and shadow, even though every other combination of 2 damage types shows up.

Maybe time to reconsider a helmet to match the Radiant Silvermail? It's always been kind of a conspicuous hole, but it looks like it has suddenly shot up in importance.

(For those who are wondering, the armors that appear to most closely match the other shadow lair themes are Skolver (pierce/freeze) for the Ice Queen, Grey Feather (normal/elemental/fire/shock) for Red Roarmulus Twins, and Divine (shadow/fire/curse) or Radiant Silvermail (shadow/curse/+damage vs undead) for Darkfire Vanaduke. Of course, this is just guessing at the shadow lair contents based on the patch notes, and without seeing any of the new armors introduced in this patch.)