On PTCGO, Magearna's ability stops Damage Change from working but Magearna's ability only states effect of opponent's attacks. Is this intended or a bug?
Moved from the TCG Help & Advice to the Ask A Professor forums as the OP is asking a rulings question. I've also added scans for the cards in question, as this forums requires scans. ~bbninjas
That's intended. Damage Change tries to move damage counters both from and to Magearna-EX, and Mystic Heart prevents it from happening. The end result is Mewtwo-EX's damage goes away, and Magearna-EX's damage is not removed.
I worded my post badly. What I mean is the Magearna is mine and on my bench and my Mewtwohas 2 psychic and 1 metal energy attached. Damage change fizzled. his field consisted of 3 scizors and 1 shaymin