Nefertari's Necklace, on his stomach.
Effects: Seasonal Powers are stronger against the dark energy, meaning everyone will be able to fight creatures coated in it easier.
Extra Effects: Elemental Resistance (ice), New Element creation and manipulation (neutral)*

*Neutral Element is what it says on the tin. It's a shapeless energy that usually takes a blank, white form (but can be different colored, too). No creature is super weak against the element, but none of them resist it either; it's the element that will always deal damage, no matter what.