Nibenay 5% mitigation is equivalent to around 3k armor, let alone the crit resist and pull shield
Orpheon is way more fun (and can be used defensively similar to charm). Save and throw down the rune focus while backpedalling after rush. You’ll get the huge benefits for standing in it, and the AOE will hit very hard. It comes off cooldown pretty perfectly after dawnbreaker/surprise attack/merciless resolve etc then netch, vigor, fissure, contingency, and rush again. The opponent is constantly block healing and never really gets a chance to go offensive.
Impen is by far the most valuable trait, and medium armor is also best in slot