Last time I checked, players activate this during your draw phase. If they miss that, they can always activate it just before your battlephase. So no, both AMA and Trunade don't stop this card.. THE best removal card right now is Cosmic Cyclone. Spend gems on that. Again.. GO FOR COSMIC CYCLONE!
If you ever played masked heroes you knew that stopping your own spells during the battle phase is quite the steep trade-off but yea the original trunade would be better