not sure if there is a card like this out, but had an idea for a spirit card today
courage in unlikely places, cost: 1, effect: target ally counts as a hero until the end of the round.
basically it would allow an ally to benefit from effects that target heroes only (daughter of nimrodel, common cause, etc.) or soak damage from undefended enemies. because of the time limitation it would make attaching items wasteful in general. let me know what u think.