Hindervines

Prevent all combat damage that would be dealt this turn by creatures with no +1/+1 counters on them.

Absolute Law

Humility

All creatures lose all abilities and have base power and toughness 1/1.

Total War

Whenever a player attacks with one or more creatures, destroy all untapped non-Wall creatures that player controls that didn't attack, except for creatures the player hasn't controlled continuously since the beginning of the turn.

Benefactor's Draught

Untap all creatures. Until end of turn, whenever a creature an opponent controls blocks, draw a card.
Draw a card.

Living Plane

All lands are 1/1 creatures that are still lands.

Riptide

Pendrell Mists

All creatures have "At the beginning of your upkeep, sacrifice this creature unless you pay {1}."

Time and Tide

Simultaneously, all phased-out creatures phase in and all creatures with phasing phase out.

Magmatic Galleon

When Magmatic Galleon enters, it deals 5 damage to target creature an opponent controls.
Whenever one or more creatures your opponents control are dealt excess noncombat damage, create a Treasure token.
Crew 2

Mass Hysteria

Darkest Hour

Arena of the Ancients

Legendary creatures don't untap during their controllers' untap steps.
When Arena of the Ancients enters, tap all legendary creatures.

Night of Souls' Betrayal

Brawl

Until end of turn, all creatures gain "{T}: This creature deals damage equal to its power to target creature."

Life and Limb

All Forests and all Saprolings are 1/1 green Saproling creatures and Forest lands in addition to their other types. (They're affected by summoning sickness.)

Bubble Matrix

Prevent all damage that would be dealt to creatures.

Noxious Ghoul

Whenever Noxious Ghoul or another Zombie enters, all non-Zombie creatures get -1/-1 until end of turn.

Tanglesap

Prevent all combat damage that would be dealt this turn by creatures without trample.

Light of Sanction

Prevent all damage that would be dealt to creatures you control by sources you control.

Harsh Mercy

Each player chooses a creature type. Destroy all creatures that aren't of a type chosen this way. They can't be regenerated.

Nightcreep

Until end of turn, all creatures become black and all lands become Swamps.

Gravity Sphere

Gorilla War Cry

Cast this spell only during combat before blockers are declared.
All creatures gain menace until end of turn. (They can't be blocked except by two or more creatures.)
Draw a card at the beginning of the next turn's upkeep.

Absolute Grace

All creatures have protection from black.

Magus of the Moat

Magnify

All creatures get +1/+1 until end of turn.

Living Lands

All Forests are 1/1 creatures that are still lands.

Magus of the Tabernacle

Invasion Plans

All creatures block each combat if able.
The attacking player chooses how each creature blocks each combat.

Angelsong

Prevent all combat damage that would be dealt this turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Season of the Witch

At the beginning of your upkeep, sacrifice Season of the Witch unless you pay 2 life.
At the beginning of the end step, destroy all untapped creatures that didn't attack this turn, except for creatures that couldn't attack.

Kormus Bell

All Swamps are 1/1 black creatures that are still lands.

Batwing Brume

Prevent all combat damage that would be dealt this turn if {W} was spent to cast this spell. Each player loses 1 life for each attacking creature they control if {B} was spent to cast this spell. (Do both if {W}{B} was spent.)

Marvin, Murderous Mimic

Marvin, Murderous Mimic has all activated abilities of creatures you control that don't have the same name as this creature.

Heavy Fog

Cast this spell only during the declare attackers step and only if you've been attacked this step.
Prevent all damage that would be dealt to you this turn by attacking creatures.

Natural Affinity

All lands become 2/2 creatures until end of turn. They're still lands.

Ixidron

As Ixidron enters, turn all other nontoken creatures face down. (They're 2/2 creatures.)
Ixidron's power and toughness are each equal to the number of face-down creatures on the battlefield.

Infinite Hourglass

At the beginning of your upkeep, put a time counter on Infinite Hourglass.
All creatures get +1/+0 for each time counter on Infinite Hourglass.
{3}: Remove a time counter from Infinite Hourglass. Any player may activate this ability but only during any upkeep step.

Intruder Alarm

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters, untap all creatures.

Grand Melee

All creatures attack each combat if able.
All creatures block each combat if able.

Hell Swarm

All creatures get -1/-0 until end of turn.

Concordant Crossroads

Blunt the Assault

You gain 1 life for each creature on the battlefield. Prevent all combat damage that would be dealt this turn.

Lumbering Satyr

All creatures have forestwalk. (They can't be blocked as long as defending player controls a Forest.)