Jund

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

Reality Shaping

When you encounter Reality Shaping, starting with you, each player may put a permanent card from their hand onto the battlefield. (Then planeswalk away from this phenomenon.)

Prahv

If you cast a spell this turn, you can't attack with creatures.
If you attacked with creatures this turn, you can't cast spells.
Whenever chaos ensues, you gain life equal to the number of cards in your hand.

Lair of the Ashen Idol

At the beginning of your upkeep, sacrifice a creature. If you can't, planeswalk.
Whenever chaos ensues, any number of target players each create a 2/2 black Zombie creature token.

Selesnya Loft Gardens

If an effect would create one or more tokens, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent, it puts twice that many of those counters on that permanent instead.
Whenever chaos ensues, until end of turn, whenever you tap a land for mana, add one mana of any type that land produced.

Stensia

Whenever a creature deals damage to one or more players for the first time each turn, put a +1/+1 counter on it.
Whenever chaos ensues, each creature you control gains "{T}: This creature deals 1 damage to target player or planeswalker" until end of turn.

Kilnspire District

When you planeswalk to Kilnspire District and at the beginning of your first main phase, put a charge counter on Kilnspire District, then add {R} for each charge counter on it.
Whenever chaos ensues, you may pay {X}. If you do, Kilnspire District deals X damage to any target.

Spatial Merging

When you encounter Spatial Merging, reveal cards from the top of your planar deck until you reveal two plane cards. Simultaneously planeswalk to both of them. Put all other cards revealed this way on the bottom of your planar deck in any order.

Furnace Layer

When you planeswalk to Furnace Layer and at the beginning of your upkeep, select target player at random. That player discards a card. If that player discards a land card this way, they lose 3 life.
Whenever chaos ensues, you may destroy target nonland permanent.

Orochi Colony

Whenever a creature you control deals combat damage to a player, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Whenever chaos ensues, target creature can't be blocked this turn.