Flesh Knuckles

The defense is the small half of what it does. The other half is aggro, and aggro only means anything when there is somebody else in the room for enemies to pick instead. Playing alone, this is a plain defense accessory. In a group it decides whether the Mothron goes for the person in end game armor or the summoner standing behind them.

Stack it with armor that already pulls attention and then pile on damage reduction, since you are volunteering to be hit. Paladin's Shield and the Frozen Turtle Shell belong in the same loadout, and the knuckles feed into Hero Shield and the Berserker's Glove later. Shimmer swaps it with Putrid Scent in both directions, so your world evil does not lock you out of either one.