Basilisk Gate

{T}: Add {C}.
{2}, {T}: Target creature gets +X/+X until end of turn, where X is the number of Gates you control. Activate only as a sorcery.

Inspired Ultimatum

Target player gains 5 life, Inspired Ultimatum deals 5 damage to any target, then you draw five cards.

Protean Hydra

Protean Hydra enters the battlefield 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.

Cliffgate

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

Simic Guildgate

Simic Guildgate enters the battlefield tapped.
{T}: Add {G} or {U}.

Ironscale Hydra

If a creature would deal combat damage to Ironscale Hydra, prevent that damage and put a +1/+1 counter on Ironscale Hydra.

Izzet Guildgate

Izzet Guildgate enters the battlefield tapped.
{T}: Add {U} or {R}.

Dolmen Gate

Prevent all combat damage that would be dealt to attacking creatures you control.

Island

Clarion Ultimatum

Choose five permanents you control. For each of those permanents, you may search your library for a card with the same name as that permanent. Put those cards onto the battlefield tapped, then shuffle.

Genesis Hydra

When you cast this spell, reveal the top X cards of your library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield. Then shuffle the rest into your library.
Genesis Hydra enters the battlefield with X +1/+1 counters on it.

Apocalypse Hydra

Apocalypse Hydra enters the battlefield with X +1/+1 counters on it. If X is 5 or more, it enters the battlefield with an additional X +1/+1 counters on it.
{1}{R}, Remove a +1/+1 counter from Apocalypse Hydra: It deals 1 damage to any target.

Violent Ultimatum

Plains

Hydra Broodmaster

{X}{X}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)
When Hydra Broodmaster becomes monstrous, create X X/X green Hydra creature tokens.

Briar Hydra

Trample
Domain — Whenever Briar Hydra deals combat damage to a player, put X +1/+1 counters on target creature you control, where X is the number of basic land types among lands you control.

Hydra Omnivore

Whenever Hydra Omnivore deals combat damage to an opponent, it deals that much damage to each other opponent.

Eerie Ultimatum

Return any number of permanent cards with different names from your graveyard to the battlefield.

Sea Gate

Sea Gate enters the battlefield tapped.
As Sea Gate enters the battlefield, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Door to Nothingness

Door to Nothingness enters the battlefield tapped.
{W}{W}{U}{U}{B}{B}{R}{R}{G}{G}, {T}, Sacrifice Door to Nothingness: Target player loses the game.

Azorius Guildgate

Azorius Guildgate enters the battlefield tapped.
{T}: Add {W} or {U}.

Hooded Hydra

Hooded Hydra enters the battlefield with X +1/+1 counters on it.
When Hooded Hydra dies, create a 1/1 green Snake creature token for each +1/+1 counter on it.
Morph {3}{G}{G}
As Hooded Hydra is turned face up, put five +1/+1 counters on it.

Gates of Istfell

Gates of Istfell enters the battlefield tapped.
{T}: Add {W}.
{2}{W}{U}{U}, {T}, Sacrifice Gates of Istfell: You gain 2 life and draw two cards.

Phytohydra

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

Vastwood Hydra

Vastwood Hydra enters the battlefield with X +1/+1 counters on it.
When Vastwood Hydra dies, you may distribute a number of +1/+1 counters equal to the number of +1/+1 counters on Vastwood Hydra among any number of creatures you control.

Boros Guildgate

Boros Guildgate enters the battlefield tapped.
{T}: Add {R} or {W}.

Progenitus

Protection from everything
If Progenitus would be put into a graveyard from anywhere, reveal Progenitus and shuffle it into its owner's library instead.

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.")

Whiptongue Hydra

Reach
When Whiptongue Hydra enters the battlefield, destroy all creatures with flying. Put a +1/+1 counter on Whiptongue Hydra for each creature destroyed this way.

Citadel Gate

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

Playable Delusionary Hydra

{TK}{TK} — {T}: Draw a card, then discard a card.
{TK}{TK}{TK}{TK} — Whenever this creature attacks, you gain 3 life and draw a card.
{TK}{TK} — 1/5
{TK}{TK}{TK} — 4/4

Mountain

Kalonian Hydra

Trample
Kalonian Hydra enters the battlefield with four +1/+1 counters on it.
Whenever Kalonian Hydra attacks, double the number of +1/+1 counters on each creature you control.

Dimir Guildgate

Dimir Guildgate enters the battlefield tapped.
{T}: Add {U} or {B}.

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.

Cruel Ultimatum

Target opponent sacrifices a creature, discards three cards, then loses 5 life. You return a creature card from your graveyard to your hand, draw three cards, then gain 5 life.

Gond Gate

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

Hydra's Growth

Enchant creature
When Hydra's Growth enters the battlefield, put a +1/+1 counter on enchanted creature.
At the beginning of your upkeep, double the number of +1/+1 counters on enchanted creature.

Voracious Hydra

Trample
Voracious Hydra enters the battlefield with X +1/+1 counters on it.
When Voracious Hydra enters the battlefield, choose one —
• Double the number of +1/+1 counters on Voracious Hydra.
• Voracious Hydra fights target creature you don't control.

Selesnya Guildgate

Selesnya Guildgate enters the battlefield tapped.
{T}: Add {G} or {W}.

Genesis Ultimatum

Look at the top five cards of your library. Put any number of permanent cards from among them onto the battlefield and the rest into your hand. Exile Genesis Ultimatum.

Titanic Ultimatum

Until end of turn, creatures you control get +5/+5 and gain first strike, trample, and lifelink.

Sol Ring

Rakdos Guildgate

Rakdos Guildgate enters the battlefield tapped.
{T}: Add {B} or {R}.

Gruul Guildgate

Gruul Guildgate enters the battlefield tapped.
{T}: Add {R} or {G}.

Managorger Hydra

Trample
Whenever a player casts a spell, put a +1/+1 counter on Managorger Hydra.

Lifeblood Hydra

Trample
Lifeblood Hydra enters the battlefield with X +1/+1 counters on it.
When Lifeblood Hydra dies, you gain life and draw cards equal to its power.

Golgari Guildgate

Golgari Guildgate enters the battlefield tapped.
{T}: Add {B} or {G}.

Lair of the Hydra

If you control two or more other lands, Lair of the Hydra enters the battlefield tapped.
{T}: Add {G}.
{X}{G}: Until end of turn, Lair of the Hydra becomes an X/X green Hydra creature. It's still a land. X can't be 0.

Ruinous Ultimatum

Destroy all nonland permanents your opponents control.

Benevolent Hydra

Benevolent Hydra enters the battlefield with X +1/+1 counters on it.
If one or more +1/+1 counters would be put on another creature you control, that many plus one +1/+1 counters are put on it instead.
{T}, Remove a +1/+1 counter from Benevolent Hydra: Put a +1/+1 counter on another target creature you control.

Goldvein Hydra

Vigilance, trample, haste
Goldvein Hydra enters the battlefield with X +1/+1 counters on it.
When Goldvein Hydra dies, create a number of tapped Treasure tokens equal to its power.

Emergent Ultimatum

Search your library for up to three monocolored cards with different names and exile them. An opponent chooses one of those cards. Shuffle that card into your library. You may cast the other cards without paying their mana costs. Exile Emergent Ultimatum.

Black Dragon Gate

Black Dragon Gate enters the battlefield tapped.
As Black Dragon Gate enters the battlefield, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Khalni Hydra

This spell costs {G} less to cast for each green creature you control.
Trample

Door of Destinies

As Door of Destinies enters the battlefield, choose a creature type.
Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.
Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Forest

Hungering Hydra

Hungering Hydra enters the battlefield with X +1/+1 counters on it.
Hungering Hydra can't be blocked by more than one creature.
Whenever Hungering Hydra is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

Orzhov Guildgate

Orzhov Guildgate enters the battlefield tapped.
{T}: Add {W} or {B}.

Manor Gate

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

Brilliant Ultimatum

Exile the top five cards of your library. An opponent separates those cards into two piles. You may play lands and cast spells from one of those piles. If you cast a spell this way, you cast it without paying its mana cost.

Swamp

Molten Hydra

{1}{R}{R}: Put a +1/+1 counter on Molten Hydra.
{T}, Remove all +1/+1 counters from Molten Hydra: It deals damage to any target equal to the number of +1/+1 counters removed this way.