Is the Strength loss caused by the Weakened effect from Blasphemy considered ability drain or damage for purposes of a Death Ward or similar effect?
Would a Scarab of Protection work against that effect?
The scarab grants a blanket spell resistance 20 as well as specifically protecting against energy-draining attacks (such as the monster ability that bestows negative levels), death effects, and negative energy effects. The spell you mentioned is none of these, so the scarab would not specifically protect the wearer from it. However, the wearer does gain spell resistance 20, and that would apply to blasphemy.