When using Chandelure's "Cursed Shadow" ability, if I place one damage counter and KO a Pokemon, would all the normal KO procedures (take a prize, opponent promotes, etc.) occur before or after you place the remaining two damage counters?

Each action must be completed before you move on to another action. In this case, placing a damage counter is not the action; the action is the triggering and use of the Cursed Shadow Ability. So you must place all three damage counters and then check for any Pokemon that are KO'd.

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