I already mentioned that: no. Facets and Infinity possess this mod, but they don't reduce Immunity any further than what was already there, if Immunity has yet not been broken (<100).

For instance, an enemy has 101 Fire Immunity remaining, and you had all 5/5 Fire Facets in your equipment, 6 (weapon), 3 (Helm), 4 (Armor), 4 (Shield); that's 17*5, equalling -85 resistance.

Guess what? If Immunity >100, that's not divided by 5, and applied as 101-85/5, Immunity is going to stay at 101.

Immunity MUST BE BROKEN for the "reduce enemy resistance" mod to effect.