"Ectoplasm" goes into effect IMMEDIATELY after Dusknoir LV. X gets Knocked Out, correct?
As an example, is this the proper order: opponent's attack does enough damage to my Active Dusknoir, I put LV. X into play as a Stadium, this counts as a Knock Out, opponent takes a Prize card, opponent's turn ends, 1 damage counter is placed on each of opponent's Pokemon, and THEN it's my turn...?