Number 40: Gimmick Puppet of Strings (LED5-EN043) - Legendary Duelists: Immortal Destiny 1st Edition

2 Level 8 monsters
Once per turn: You can detach 1 Xyz Material from this card; place 1 String Counter on each face-up monster on the field, except this card. If you do, during your opponent's next End Phase: Destroy the monsters with String Counters, and if you do, inflict 500 damage to your opponent for each monster destroyed.