Pyrohemia

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pyrohemia.
{R}: Pyrohemia deals 1 damage to each creature and each player.

Branching Evolution

If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on that creature instead.

Don't Have

Gateway Plaza

Gateway Plaza enters tapped.
When Gateway Plaza enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Phytohydra

If damage would be dealt to Phytohydra, put that many +1/+1 counters on it instead.

Urban Daggertooth

Vigilance
Enrage — Whenever Urban Daggertooth is dealt damage, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Magma Pummeler

Magma Pummeler enters with X +1/+1 counters on it.
If damage would be dealt to Magma Pummeler while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from it. When one or more counters are removed from Magma Pummeler this way, it deals that much damage to any target.

Aether Flash

Whenever a creature enters, Aether Flash deals 2 damage to it.

Have

Heap Gate

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{1}, {T}, Tap an untapped Gate you control: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Rite of Passage

Whenever a creature you control is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)

Ranging Raptors

Enrage — Whenever Ranging Raptors is dealt damage, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Manor Gate

Manor Gate enters tapped.
As Manor Gate enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Citadel Gate

Citadel Gate enters tapped.
As Citadel Gate enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Cliffgate

Cliffgate enters tapped.
As Cliffgate enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Cinderclasm

Kicker {R} (You may pay an additional {R} as you cast this spell.)
Cinderclasm deals 1 damage to each creature. If it was kicked, it deals 2 damage to each creature instead.

Bellowing Aegisaur

Enrage — Whenever Bellowing Aegisaur is dealt damage, put a +1/+1 counter on each other creature you control.

Baldur's Gate

{T}: Add {C}.
{2}, {T}: Add X mana of any one color, where X is the number of other Gates you control.

Imperial Ceratops

Enrage — Whenever Imperial Ceratops is dealt damage, you gain 2 life.

Gond Gate

Gates you control enter untapped.
{T}: Add {C}.
{T}: Add one mana of any color that a Gate you control could produce.

Protean Hydra

Protean Hydra enters with X +1/+1 counters on it.
If damage would be dealt to Protean Hydra, prevent that damage and remove that many +1/+1 counters from it.
Whenever a +1/+1 counter is removed from Protean Hydra, put two +1/+1 counters on it at the beginning of the next end step.