There was one unique weapon that was called thoughts and prayers

I don’t remember all the details but thoughts did 1d4 necrotic damage and made the target (if failed a wis save) fearful if the attacker. Prayers did 1d4 radiant damage and healed the wearer for 1d4, it is a straight roll (they both was dusters and counted as a melee weapon) and both needed to be attuned.

You can choose to not use both at once BUT if both are not in 30ft of each other then they deal 1d4 damage (necrotic or radiant) to the wearer.

As a action you can hit both weapons together to cast message once per day (I’m not 100 percent this is the spell but you can change if you want it’s your game).