This effect targets 1 other face-upAttack Position monster on the field. It can only target 1 monster on the turn player's side of the field. (If it is activated during your turn, it can only target 1 monster in your Monster Zone.)
You can Special Summon "Performage Trapeze Magician" with the Trigger Effect of "Performage Trick Clown". Its ATK and DEF will become 0, also the monster effect of "Performage Trapeze Magician", ""You never take damage if the amount is less than or equal to this card's ATK.", is not applied yet and you will take 1,000 damage as usual from the effect of "Performage Trick Clown".