Weakening Spell Resistance with melee attacks

Question

For the life of me I can't remember where, but I remember reading somewhere, maybe under runes or Magus that there was a way that melee attacks would weaken a target's Spell Resistance? Can anyone shed any light on this?

Answer 1

Splinter Spell Resistance (2nd level spell)

The first time each round the weapon damages a creature with spell resistance, that creature’s spell resistance is reduced by 5 for 1 round. This reduction is not cumulative for multiple attacks within the same round.

Rending the Shround (3pp Magus arcana)

Whenever the magus makes a successful melee attack, she may spend 1 point from her arcane pool as a swift action to reduce her target’s spell resistance with no save allowed. The target’s spell resistance is reduced by the magus’s Intelligence modifier for a number of rounds equal to ½ her magus level.

Shattermantle (3.5e weapon special ability. sourcebook: Waterdeep)

Each time the weapon strikes a foe with spell resistance, the value of that spell resistance is reduced by 2 for 1 round. The penalties for multiple hits during the same round stack. Price: +1 bonus.

Breach Power Resistance (Illithid Slayer aka Phrenic Slayer PrC)

A slayer of 8th level or higher can enhance her weapon with psionic might. Each successful melee attack (or ranged attack if the target is within 30 feet) she makes with her weapon against a creature with power resistance temporarily reduces its power resistance by 1. Unless the creature is slain, its lost power resistance returns all at once 12 hours later. This ability is active as long as the slayer is psionically focused.