I was playing through the mod and right around where I entered hard mode I noticed I no longer take any damage from any projectile coming from any enemy. First noticed when grinding WOF for emblems, his lasers stopped damaging me. I couldn't tell you for sure if this is a mod issue or if this is a game issue, but I've never had this bug before on any other modpack or in vanilla, and it definitely wasn't happening in the early game.