The main use of Klang is in the Spinning Gears attack that is has, which has the ability to make the opponent's active Pokemon confused in addition to dealing 20 damage
Duress, Thoughtsieze and even Inquisition are the best way to deal with the very few combo decks that can outpace you as well as the control decks that have some brutal counters to you
However, with this, they cannot hide their beef or Eldrazi Titans behind a smaller sacrifice, their biggest power gets sacrificed
Part of the Mega Dream ex expansion, featuring a full card list published for M2a
However, cards like Cyrus and Sabrina can easily disrupt this setup, making it difficult to win if even one of the Greninja's is knocked out by the opponent
If Charizard can take those 2 prizes with a Charmander instead of promoting a Charizard, that's a safer play if the roaring moon user is not at 1 prize remaining