Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

When Acidic Slime enters the battlefield, destroy target artifact, enchantment, or land.

Whenever another permanent enters the battlefield under your control, each opponent mills a card.

Whenever one or more +1/+1 counters are put on a permanent you control, you may pay {1}. If you do, create a 1/1 colorless Servo artifact creature token.

{3}, {T}: Choose a counter on target permanent or player. Give that permanent or player another counter of that kind.

Spells and abilities your opponents control can't cause their controller to search their library.

-1: Target player mills four cards. Then exile each opponent's graveyard.

You may play two additional lands on each of your turns.

Whenever a nonartifact permanent enters the battlefield under your control, you may return another permanent you control that shares a permanent type with it to its owner's hand.

When Contagion Engine enters the battlefield, put a -1/-1 counter on each creature target player controls.

{4}, {T}: Proliferate, then proliferate again. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

You may play lands from your graveyard.

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

Flying

Whenever you gain life, target opponent loses that much life.

Search your library and graveyard for five cards and exile the rest. Put the chosen cards on top of your library in any order. You lose half your life, rounded up.

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.

Each player mills X cards. For each creature card put into a graveyard this way, you create a tapped 2/2 black Zombie creature token.

Whenever you gain life, each opponent loses 1 life.

Landfall -- Whenever a land enters the battlefield under your control, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

+2: Create a 1/1 green Elf Druid creature token with "{T}: Add {G}."

-2: Destroy target artifact or enchantment.

-6: Draw a card for each green creature you control.

Freyalise, Llanowar's Fury can be your commander.

Whenever a nontoken creature enters the battlefield under your control, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Whenever Hapatra, Vizier of Poisons deals combat damage to a player, you may put a -1/-1 counter on target creature.

Whenever you put one or more -1/-1 counters on a creature, create a 1/1 green Snake creature token with deathtouch.

Creatures don't untap during their controllers' untap steps.

Whenever a creature enters the battlefield, untap all creatures.

+2: Look at the top card of target player's library. You may put that card on the bottom of that player's library.

0: Draw three cards, then put two cards from your hand on top of your library in any order.

-1: Return target creature to its owner's hand.

-12: Exile all cards from target player's library, then that player shuffles their hand into their library.

Each creature you control with a +1/+1 counter on it has "{T}: Add one mana of any color."

-1: Put a +1/+1 counter on target creature.

Landfall -- Whenever a land enters the battlefield under your control, you may put a quest counter on Khalni Heart Expedition.

Remove three quest counters from Khalni Heart Expedition and sacrifice it: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Whenever a creature with power 4 or greater enters the battlefield under your control, draw a card.

-1: Untap target permanent.

If Leyline of Abundance is in your opening hand, you may begin the game with it on the battlefield.

Whenever you tap a creature for mana, add an additional {G}.

{6}{G}{G}: Put a +1/+1 counter on each creature you control.

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.

You may cast spells as though they had flash.

If Leyline of Vitality is in your opening hand, you may begin the game with it on the battlefield.

Creatures you control get +0/+1.

Whenever a creature enters the battlefield under your control, you may gain 1 life.

Whenever a creature you control dies, draw a card.

+1: Create a 2/2 black Zombie creature token.

-4: Each player sacrifices two creatures.

-9: Each opponent chooses a permanent they control of each permanent type and sacrifices the rest.

+2: Target creature can't be blocked this turn.

-3: Draw two cards.

-10: Tap all creatures your opponents control. You take an extra turn after this one.

During each of your turns, you may play a land and cast a permanent spell of each permanent type from your graveyard. (If a card has multiple permanent types, choose one as you play it.)

Each opponent can't draw more than one card each turn.

-2: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Skip your draw step.

Whenever you discard a card, exile that card from your graveyard.

Pay 1 life: Exile the top card of your library face down. Put that card into your hand at the beginning of your next end step.

Whenever you put one or more -1/-1 counters on a creature, create that many 1/1 black Insect creature tokens.

+2: Scry 2.

0: Look at the top card of your library. If it's a land card or a creature card with mana value less than or equal to the number of loyalty counters on Nissa, Steward of Elements, you may put that card onto the battlefield.

-6: Untap up to two target lands you control. They become 5/5 Elemental creatures with flying and haste until end of turn. They're still lands.

When Nissa, Vastwood Seer enters the battlefield, you may search your library for a basic Forest card, reveal it, put it into your hand, then shuffle.

Whenever a land enters the battlefield under your control, if you control seven or more lands, exile Nissa, then return her to the battlefield transformed under her owner's control.

+1: Reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put it into your hand.

-2: Create Ashaya, the Awoken World, a legendary 4/4 green Elemental creature token.

-7: Untap up to six target lands. They become 6/6 Elemental creatures. They're still lands.

+1: Create a 0/1 green Plant creature token.

-2: Put a +1/+1 counter on each creature you control.

-7: You gain X life and draw X cards, where X is the number of lands you control.

+2: Each opponent loses 1 life. You gain life equal to the life lost this way.

-2: Create a 5/5 black Demon creature token with flying. You lose 2 life.

-8: You get an emblem with "{1}{B}, Sacrifice a creature: You gain X life and draw X cards, where X is the sacrificed creature's power."

Ob Nixilis of the Black Oath can be your commander.

Flying, trample

Whenever an opponent searches their library, that player sacrifices a creature and loses 10 life.

Whenever another creature dies, put a +1/+1 counter on Ob Nixilis, Unshackled.

Landfall -- Whenever a land enters the battlefield under your control, you may have target player lose 3 life. If you do, put three +1/+1 counters on Ob Nixilis, the Fallen.

Flying

{X}{U/B}: Choose a color. Target opponent exiles the top X cards of their library. For each card of the chosen color exiled this way, create a 1/1 blue and black Faerie Rogue creature token with flying.

If an artifact or creature entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Put all creature cards from all graveyards onto the battlefield under your control.

Whenever you gain life, target opponent loses that much life.

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.

At the beginning of each opponent's upkeep, that player sacrifices a creature.

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

When Solemn Simulacrum dies, you may draw a card.

+1: Untap up to two target artifacts.

-X: Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.

-5: Artifacts you control become artifact creatures with base power and toughness 5/5 until end of turn.

+1: Create a 1/1 colorless Thopter artifact creature token with flying.

0: Draw a card. If you control three or more artifacts, draw two cards instead.

-9: You get an emblem with "At the beginning of your end step, search your library for a permanent card, put it onto the battlefield, then shuffle."

At the beginning of your end step, if you didn't activate a loyalty ability of a planeswalker this turn, you lose 2 life.

{4}, {T}: For each planeswalker you control, you may activate one of its loyalty abilities once this turn as though none of its loyalty abilities have been activated this turn.

Deathtouch

At the beginning of your upkeep, sacrifice The Gitrog Monster unless you sacrifice a land.

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

Whenever one or more land cards are put into your graveyard from anywhere, draw a card.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)

I -- Return target instant card from your graveyard to your hand.

II -- Return target sorcery card from your graveyard to your hand.

III -- Until end of turn, whenever you cast an instant or sorcery spell, copy it. You may choose new targets for the copy.

Enchant creature

When Treachery enters the battlefield, untap up to five lands.

You control enchanted creature.

If a Zombie you control would deal combat damage to a player, instead that player mills that many cards.

Whenever a creature card is put into an opponent's graveyard from their library, exile that card and create a 2/2 black Zombie creature token.

Target opponent exiles the top X cards of their library. You may cast any number of spells with mana value X or less from among them without paying their mana costs.

When Yarok's Wavecrasher enters the battlefield, return another creature you control to its owner's hand.

Deathtouch, lifelink

If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Protection from Humans

Pay 1 life, Sacrifice another creature: Put a -1/-1 counter on up to one target creature and draw a card.

{B}{B}, Discard a card: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.