Last March of the Ents

This spell can't be countered.
Draw cards equal to the greatest toughness among creatures you control, then put any number of creature cards from your hand onto the battlefield.

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Apex Devastator

Cascade, cascade, cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Multiple instances of cascade each trigger separately.)

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Exploration

You may play an additional land on each of your turns.

Frankenstein's Monster

As Frankenstein's Monster enters, exile X creature cards from your graveyard. If you can't, put Frankenstein's Monster into its owner's graveyard instead of onto the battlefield. For each creature card exiled this way, Frankenstein's Monster enters with a +2/+0, +1/+1, or +0/+2 counter on it.

Show and Tell

Each player may put an artifact, creature, enchantment, or land card from their hand onto the battlefield.

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

Seething Song

True Conviction

Creatures you control have double strike and lifelink.

Black Market

Whenever a creature dies, put a charge counter on Black Market.
At the beginning of your first main phase, add {B} for each charge counter on Black Market.

Stinkweed Imp

Flying
Whenever Stinkweed Imp deals combat damage to a creature, destroy that creature.
Dredge 5 (If you would draw a card, you may mill five cards instead. If you do, return this card from your graveyard to your hand.)

Hunting Grounds

Threshold — As long as seven or more cards are in your graveyard, Hunting Grounds has "Whenever an opponent casts a spell, you may put a creature card from your hand onto the battlefield."

Sacrifice

As an additional cost to cast this spell, sacrifice a creature.
Add an amount of {B} equal to the sacrificed creature's mana value.

Omniscience

You may cast spells from your hand without paying their mana costs.

Lurking Predators

Whenever an opponent casts a spell, reveal the top card of your library. If it's a creature card, put it onto the battlefield. Otherwise, you may put that card on the bottom of your library.

Akroma's Memorial

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

Burgeoning

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.

Dark Ritual

Impervious Greatwurm

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Indestructible

Repay in Kind

Each player's life total becomes the lowest life total among all players.

Mana Geyser

Add {R} for each tapped land your opponents control.

Worldspine Wurm

Trample
When Worldspine Wurm dies, create three 5/5 green Wurm creature tokens with trample.
When Worldspine Wurm is put into a graveyard from anywhere, shuffle it into its owner's library.

Sterling Grove

Other enchantments you control have shroud. (They can't be the targets of spells or abilities.)
{1}, Sacrifice Sterling Grove: Search your library for an enchantment card, reveal it, then shuffle and put that card on top.

Majestic Genesis

Reveal the top X cards of your library, where X is the greatest mana value of a commander you own on the battlefield or in the command zone. You may put any number of permanent cards from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Nirkana Revenant

Whenever you tap a Swamp for mana, add an additional {B}.
{B}: Nirkana Revenant gets +1/+1 until end of turn.

Carpet of Flowers

At the beginning of each of your main phases, if you haven't added mana with this ability this turn, you may add X mana of any one color, where X is the number of Islands target opponent controls.

Avacyn's Memorial

Indestructible
Other legendary permanents you control have indestructible.

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Call Forth the Tempest

Cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order. Then do it again.)
Call Forth the Tempest deals damage to each creature your opponents control equal to the total mana value of other spells you've cast this turn.

Soldevi Adnate

{T}, Sacrifice a black or artifact creature: Add an amount of {B} equal to the sacrificed creature's mana value.

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Heartless Summoning

Creature spells you cast cost {2} less to cast.
Creatures you control get -1/-1.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Mana Echoes

Whenever a creature enters, you may add an amount of {C} equal to the number of creatures you control that share a creature type with it.

Songs of the Damned

Add {B} for each creature card in your graveyard.

Kindred Summons

Choose a creature type. Reveal cards from the top of your library until you reveal X creature cards of the chosen type, where X is the number of creatures you control of that type. Put those cards onto the battlefield, then shuffle the rest of the revealed cards into your library.

Inkshield

Prevent all combat damage that would be dealt to you this turn. For each 1 damage prevented this way, create a 2/1 white and black Inkling creature token with flying.

Ghalta, Stampede Tyrant

Trample
When Ghalta, Stampede Tyrant enters, put any number of creature cards from your hand onto the battlefield.

Rain of Filth

Until end of turn, lands you control gain "Sacrifice this land: Add {B}."

Burnt Offering

As an additional cost to cast this spell, sacrifice a creature.
Add X mana in any combination of {B} and/or {R}, where X is the sacrificed creature's mana value.