so after two dozen heolstor runs using ironeye, I can confirm night of the lord is basically the same as x element on starting weapon. and that elemental damage shreds the game for some reason.
both deal 200 damage against heolstor on average with the edge going for notl. but holy on starting weapon will easily out damage it if you get a few decent passives. best notl run I had an erdtree bow with a ton of affinity bonuses and I was hitting for 247, best holy on starting weapon run I was hitting for 227.
for some reason elemental damage ramps up around level 12 and starts hitting like a truck against everything while notl stays consistent throughout