Chaotic Aether

When you encounter Chaotic Aether, each blank roll of the planar die is a {CHAOS} roll until a player planeswalks away from a plane. (Then planeswalk away from this phenomenon.)

Riptide Island

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.

The Great Aerie

When you planeswalk to The Great Aerie and at the beginning of your upkeep, bolster 3. (Choose a creature with the least toughness among creatures you control and put three +1/+1 counters on it.)
Whenever chaos ensues, choose up to one target creature you control and up to one target creature an opponent controls. Each of those creatures deals damage equal to its toughness to the other.

Towashi

Modified creatures you control have trample and "Whenever this creature deals combat damage to a player or planeswalker, draw a card." (Equipment, Auras you control, and counters are modifications.)
Whenever chaos ensues, distribute three +1/+1 counters among one, two, or three target creatures you control.

The Golden City of Orazca

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token. Then draw a card if you have the city's blessing.
Whenever chaos ensues, you may put a permanent card from your hand onto the battlefield tapped.

Megaflora Jungle

Each creature with mana value 2 or less gets +2/+2.
Whenever chaos ensues, create a 1/1 green Insect creature token with flying named Butterfly.

Grove of the Dreampods

When you planeswalk to Grove of the Dreampods and at the beginning of your upkeep, reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield and the rest on the bottom of your library in a random order.
Whenever chaos ensues, return target creature card from your graveyard to the battlefield.

Jund

Whenever a player casts a creature spell that's black, red, or green, it gains devour 5. (As the creature enters, its controller may sacrifice any number of creatures of their choice. The creature enters with five times that many +1/+1 counters on it.)
Whenever chaos ensues, create two 1/1 red Goblin creature tokens.

Bloodhill Bastion

Whenever a creature enters, it gains double strike and haste until end of turn.
Whenever chaos ensues, exile target nontoken creature you control, then return it to the battlefield under your control.

Kharasha Foothills

Whenever a creature you control attacks a player, for each other opponent, you may create a token that's a copy of that creature, tapped and attacking that opponent. Exile those tokens at the beginning of the next end step.
Whenever chaos ensues, you may sacrifice any number of creatures. If you do, Kharasha Foothills deals that much damage to target creature.