Path of the Pyromancer

Discard all the cards in your hand. Add {R} for each card discarded this way, then draw that many cards plus one.
Will of the Planeswalkers — Starting with you, each player votes for planeswalk or chaos. If planeswalk gets more votes, planeswalk. If chaos gets more votes or the vote is tied, chaos ensues.

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Mana Geyser

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

Battle Hymn

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Emerald Medallion

Green spells you cast cost {1} less to cast.

Tropical Island

Seething Song

Thrumming Stone

Spells you cast have ripple 4. (Whenever you cast a spell, you may reveal the top four cards of your library. You may cast spells with the same name as that spell from among the revealed cards without paying their mana costs. Put the rest on the bottom of your library.)

Primal Vigor

If one or more tokens would be created, twice that many of those tokens are created instead.
If one or more +1/+1 counters would be put on a creature, twice that many +1/+1 counters are put on that creature instead.

Geosurge

Add {R}{R}{R}{R}{R}{R}{R}. Spend this mana only to cast artifact or creature spells.

Storm, Force of Nature

Flying, vigilance
Ceaseless Tempest — Whenever Storm deals combat damage to a player, the next instant or sorcery spell you cast this turn has storm. (When you cast it, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Island

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
Ketria Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Mountain

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

Adrix and Nev, Twincasters

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
If one or more tokens would be created under your control, twice that many of those tokens are created instead.

Dragonrage

Add {R} for each attacking creature you control. Until end of turn, attacking creatures you control gain "{R}: This creature gets +1/+0 until end of turn."

Slime Against Humanity

Create a 0/0 green Ooze creature token with trample. Put X +1/+1 counters on it, where X is two plus the total number of cards you own in exile and in your graveyard that are Oozes or are named Slime Against Humanity.
A deck can have any number of cards named Slime Against Humanity.

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

Pyretic Ritual

Taiga

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Spire Garden

Spire Garden enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Fire-Lit Thicket

{T}: Add {C}.
{R/G}, {T}: Add {R}{R}, {R}{G}, or {G}{G}.

Doppelgang

For each of X target permanents, create X tokens that are copies of that permanent.

Awaken the Woods

Create X 1/1 green Forest Dryad land creature tokens. (They're affected by summoning sickness.)

Fabled Passage

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Frontier Bivouac

Frontier Bivouac enters tapped.
{T}: Add {G}, {U}, or {R}.

Parallel Lives

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Rejuvenating Springs

Rejuvenating Springs enters tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Inner Fire

Double Major

Copy target creature spell you control, except it isn't legendary if the spell is legendary. (A copy of a creature spell becomes a token.)

Rite of Flame

Add {R}{R}, then add {R} for each card named Rite of Flame in each graveyard.

Cascade Bluffs

{T}: Add {C}.
{U/R}, {T}: Add {U}{U}, {U}{R}, or {R}{R}.

Desperate Ritual

Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Flooded Grove

{T}: Add {C}.
{G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{U}.

Jeska's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Add {R} for each card in target opponent's hand.
• Exile the top three cards of your library. You may play them this turn.

Gaea's Cradle

{T}: Add {G} for each creature you control.

Forest

Cloud Key

As Cloud Key enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Volcanic Island

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.