For the session I ran on Halloween, a chain demon showed up in the village plagued by imps, thanks to a paladin stepping in and driving them off. (They called for reinforcements.)
Of course, the paladin just charged in and grabbed the chain demon by the chains, then eventually sent the fire of his god into the creature. (I just had him Defy Danger with WIS, and inflicted d6 damage even when he got a 10+, because channeling divine energy like that is not to be trifled with. It totally annihilated the Demon, though.)
So metal.
Ha! Metal! Because chains.
Both literally and tonally. Because really, what’s more metal than grabbing the chains of a chain demon with your bare hands and sending divine fire coursing through them?