Forum:Scrap-Iron Scarecrow & E. Hero Wildheart

I already know that Elemental Hero Wildheart is unaffected by Negate Attack. So my question is since Scrap-Iron Scarecrow is basically a re-useable Negate Attack, Is it too useless against Wildheart and is it sent to the graveyard if your opponent activates it against Wildheart?