The Mirari Conjecture [Mystery Booster] Phyrexian Dragon Skeleton return them to their owners'

return them to their owners' graveyards

It exemplifies the motto of the Luminary League: "Innovation requires insatiable curiosity and a good source of light

for it will one day be your shield and another day your blanket

Set: Commander 2019 Type: Creature — Beast Rarity: Uncommon Cost: {4}{G} Whenever another creature with power 3 or greater enters the battlefield under your control

As Hallowed Fountain enters the battlefield

The Mirari Conjecture [Mystery Booster] Phyrexian Dragon Skeleton return them to their owners'Set: Mystery Booster Type: Enchantment Saga Rarity: Rare Cost: {4}{U} (As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I Return target instant card from your graveyard to your hand. II Return target sorcery card from your graveyard to your hand. III Until end of turn, whenever you cast an instant or sorcery spell, copy it. You may choose new targets for the copy.