Spoiler warning. This page gives away the puzzle from 12 September 2025. If you have not played it yet, try it first – five guesses, and it is still there.
A machine that can special summon itself when opponent controls monsters.
Type: Effect Monster
Set: 2-Player Starter Deck: Yuya & Declan
CardMarket price: 0.02$
Text: If only your opponent controls a monster, you can Special Summon this card (from your hand).