'Dominaria' cards

At the beginning of your end step, if you have no cards in hand, draw seven cards. Whenever chaos ensues, discard your hand.

Whenever a nontoken creature enters, its controller creates a token that's a copy of that creature. Whenever chaos ensues, destroy target creature and all other creatures with the same name as that creature.

All creatures get +2/+2. Whenever chaos ensues, you may add {W}{U}{B}{R}{G}.

Whenever a historic creature you control attacks, it gets +2/+2 until end of turn. (Artifacts, legendaries, and Sagas are historic.) Whenever chaos ensues, reveal cards from the top of your library until you reveal a historic card. Put that card into your hand and the rest on the bottom of your library in a random order.

Instant and sorcery cards in graveyards have flashback. The flashback cost is equal to the card's mana cost. (Its owner may cast the card from their graveyard for its mana cost. Then they exile it.) Whenever chaos ensues, take an extra turn after this one.

When you planeswalk to Riptide Island and at the beginning of your upkeep, create two 1/1 colorless Sliver creature tokens. Whenever chaos ensues, Slivers you control gain haste and get +X/+X until end of turn, where X is the number of Slivers you control.

Any time you could cast a sorcery, you may exile a nonland card from your hand with X time counters on it, where X is its mana value. If the exiled card doesn't have suspend, it gains suspend. (At the beginning of its owner's upkeep, they remove a time counter. When the last is removed, the player may cast it without paying its mana cost. If it's a creature, it has haste.) Whenever chaos ensues, remove two time counters from each suspended card you own.