Citadel Siege [Commander 2016] Dwarf Set: Commander 2015 Type: Enchantment

Set: Commander 2015 Type: Enchantment Rarity: Rare Cost: {4}{U}{U}{U} When Day of the Dragons enters the battlefield

How could they improve it

Set: Friday Night Magic 2015 Type: Instant Rarity: Rare Cost: {1}{U} Counter target spell with mana value 4 or greater

{3}{W}{W}: Return Eternal Dragon from your graveyard to your hand

the Falling Star dies

Citadel Siege [Commander 2016] Dwarf Set: Commander 2015 Type: EnchantmentSet: Commander 2016 Type: Enchantment Rarity: Rare Cost: {2}{W}{W} As Citadel Siege enters the battlefield, choose Khans or Dragons. Khans At the beginning of combat on your turn, put two +1 +1 counters on target creature you control. Dragons At the beginning of combat on each opponent's turn, tap target creature that player controls.