Clockwork Avian [Antiquities] World Enchantment players can't cast spells or

players can't cast spells or activate abilities that aren't mana abilities

then put the card on top of it

if Clockwork Avian attacked or blocked this combat

As Stuffy Doll enters the battlefield

Clockwork Avian [Antiquities] World Enchantment players can't cast spells orSet: Antiquities Type: Artifact Creature Bird Rarity: Rare Cost: {5} Flying Clockwork Avian enters the battlefield with four +1 +0 counters on it. At end of combat, if Clockwork Avian attacked or blocked this combat, remove a +1 +0 counter from it. {X}, {T}: Put up to X +1 +0 counters on Clockwork Avian. This ability can't cause the total number of +1 +0 counters on Clockwork Avian to be greater than four. Activate this ability only during your upkeep.