mtg.wtf

Double any effect that doubles. (It quadruples.)

All creatures get -2/-0 until end of turn.

Swampwalk

Whenever Marsh Viper deals damage to a player, that player gets two poison counters.

Tap any number of untapped creatures you control. You gain 4 life for each creature tapped this way.

Whenever Marshland Hordemaster or another Lizard you control enters, Marshland Hordemaster perpetually gains battle cry.
Whenever Marshland Hordemaster or another Lizard you control dies, target opponent loses 1 life and you gain 1 life.

Woman Who Walked the Earth — When Martha Jones enters, investigate.
Whenever you sacrifice a Clue, Martha Jones and up to one other target creature can't be blocked this turn.
Doctor's companion

Until end of turn, target creature you control gains "{0}: The next 1 damage that would be dealt to target creature, planeswalker, or player this turn is dealt to this creature instead." Only you may activate this ability.

Conjure a card named Marwyn, the Nurturer and X cards named Llanowar Elves onto the battlefield.

{1}{B/R}: Switch a Killbot or Mary O'Kill in your hand with one on the battlefield. (If a creature is tapped, the switched creature is tapped. The same is true for untapped, attacking, blocking, enchanted, equipped, and targeted. Any counters on a creature are on the switched creature instead.)

Whenever equipped creature deals combat damage to a player, it connives X, where X is the amount of damage it dealt to that player.
Equip {2}

Vigilance
Menace
{1}, Exile Masked Bandits from your hand: Target land gains "{T}: Add {B}, {R}, or {G}" until Masked Bandits is cast from exile. You may cast Masked Bandits for as long as it remains exiled.

At the beginning of the Horde's first main phase, reveal an additional card from the top of the Horde's library. The Horde casts that card.
Hero's Reward — When Massacre Totem is put into a graveyard from anywhere, put the top seven cards of the Horde's library into its graveyard.

Commander creatures you own have "This creature enters with an additional +1/+1 counter on it" and "Other creatures you control enter with an additional +1/+1 counter on them."

Flying
When Master of Winds enters, draw two cards, then discard a card.
Whenever you cast an instant, sorcery, or Wizard spell, you may have Master of Winds's base power and toughness become 5/1 or 1/5 until end of turn.

{2}{G}{G}: Create a 1/1 green Wolf creature token named Wolves of the Hunt. It has "bands with other creatures named Wolves of the Hunt."

Haste
Reveal Masterful Ninja from your hand: Masterful Ninja is on the battlefield and in your hand until end of turn.
{1}{B}: Masterful Ninja gets +1/+1 until end of turn.

Damage can't be prevented this turn.
Creatures you control have double strike, trample, and must attack if able until end of turn.

Whenever you cast an instant or sorcery spell with mana value 3 or greater, roll a d20.
1-9 | Each player draws a card.
10-19 | You draw a card.
20 | Copy that spell. You may choose new targets for the copy.

When you set this scheme in motion, target opponent chooses self or others. If that player chooses self, that player sacrifices two lands of their choice. If the player chooses others, each of your other opponents sacrifices a land of their choice.

Destroy target creature or planeswalker. If today's date is May 6th, scry 1. If today's date is May 7th, fateseal 1. (To fateseal 1, look at the top card of an opponent's library. You may put that card on the bottom of their library.)

Whenever an enchanted creature attacks one of your opponents, it gets +2/+0 and gains trample until end of turn.
Whenever an Aura you control is put into your graveyard from the battlefield, exile it. Until the end of your next turn, you may cast that card.

Tempting offer — When Maître Tree enters the battlefield, create a token from the menu. Each opponent may also create a token from the menu. For each opponent who does, you create a token of the same type.
• Treasure
• Food
• 1/1 green Squirrel
• 3/3 green Beast

At the beginning of combat on your turn, put your choice of a +1/+1, first strike, vigilance, or menace counter on Me, the Immortal.
Counters remain on Me as it moves to any zone other than a player's hand or library.
You may cast Me from your graveyard by discarding two cards in addition to paying its other costs.

Enchant creature
Enchanted creature has islandwalk and "Whenever this creature attacks, exile it and Meandered Towershell. Return it to the battlefield under your control tapped and attacking at the beginning of the declare attackers step on your next turn, then return Meandered Towershell to the battlefield under its owner's control attached to that creature."