Armageddon Clock [Antiquities] SWSH065 return it to the battlefield

return it to the battlefield under its owner's control with a -1/-1 counter on it

Whenever Ma Chao

While you control another "Number" Xyz Monster

look for Junk Speeder

you can destroy all cards on the field

Armageddon Clock [Antiquities] SWSH065 return it to the battlefieldSet: Antiquities Type: Artifact Rarity: Uncommon Cost: {6} At the beginning of your upkeep, put a doom counter on Armageddon Clock. At the beginning of your draw step, Armageddon Clock deals damage equal to the number of doom counters on it to each player. {4}: Remove a doom counter from Armageddon Clock. Any player may activate this ability but only during any upkeep step.