Vendilion Clique [Modern Masters 2015] Mercadian Masques return each creature your opponents

return each creature your opponents control with toughness X or less to its owner's hand

Then exile it

puts it on the bottom of their library

When Oathkeeper

−4: Creatures you control get +3/+3 and gain trample until end of turn

Vendilion Clique [Modern Masters 2015] Mercadian Masques return each creature your opponentsSet: Modern Masters 2015 Type: Legendary Creature Faerie Wizard Rarity: Mythic Cost: {1}{U}{U} Flash Flying When Vendilion Clique enters the battlefield, look at target player's hand. You may choose a nonland card from it. If you do, that player reveals the chosen card, puts it on the bottom of their library, then draws a card.