-55% lightning resistance on Infinity

[Spiritanto]

What does it mean?

If I'm a lightning sorc, and my merc uses infinity. Suppose a monster has 100% lightning res and the conviction aura takes away 17%.

Does it mean the -55% lightning resist will kick in after that? Meaning that my sorc's lightning damage will be more effective?

[FrostBurn]

Yes, it will kick in provided the immunity is broken, but ONLY for the wielder of the weapon. So your sorc will benefit from the broken immunity, but NOT from the subsequent -55% to ELR that your merc benefits from (since the merc wields the Infinity).