Chains of the Ledgerfiend

These dark chains seem to shift and writhe as if imbued with a will of their own. While wearing these chains, you gain a +1 bonus to your AC. Additionally, once per long rest, you can use a bonus action to target one creature you can see within 30 feet of you. That creature must succeed on a DC 13 Strength saving throw or be restrained by ghostly chains until the end of its next turn. If the target is already restrained, you can deal 1d6 psychic damage to it, as it feels the weight of its broken promises.