: Return this creature to its owner's hand.
Cascade

You may put two +1/+1 counters on a creature you control. Then all creatures get -4/-4 until end of turn.

Red instant and sorcery spells you control have lifelink.
Whenever a white instant or sorcery spell causes you to gain life, Firesong and Sunspeaker deals 3 damage to target creature or player.

Flying, trample
Cumulative upkeep

Convoke
Flying, vigilance
Whenever this creature attacks, the next spell you cast this turn has convoke.

Each opponent mills three cards, then you may cast a spell from each opponent's graveyard without paying its mana cost. If a spell cast this way would be put into a graveyard, exile it instead.

Creatures you control get +2/+2 until end of turn.

Sneak
When this creature enters, you gain 3 life.

When this creature enters, it deals damage to any target equal to the number of creatures you control.
: This creature gets +1/+0 until end of turn.
: This creature gets +0/+1 until end of turn.

Trample
When this creature enters, tap target creature an opponent controls. Put a stun counter on it.

Create three 1/1 colorless Thopter artifact creature tokens with flying. Surveil 2.

When Gallifrey Stands enters, return all Doctor cards from your graveyard to your hand.
At the beginning of your upkeep, you may put a Doctor creature card from your hand onto the battlefield. Then if you control thirteen or more Doctors, you win the game.

When Gladiolus Amicitia enters, search your library for a land card, put it onto the battlefield tapped, then shuffle.
Landfall — Whenever a land you control enters, another target creature you control gets +2/+2 and gains trample until end of turn.

Whenever a creature you control attacks, put a +1/+1 counter on it.

Put target creature card from a graveyard onto the battlefield under your control. It gains haste.
Basic landcycling

Draw three cards. Then target opponent faces a villainous choice — They discard three cards, or you may cast a spell from your hand without paying its mana cost.

When Grenzo enters and at the beginning of your upkeep, heist target opponent's library.
Once each turn, you may pay rather than pay the mana cost for a spell you cast that you don't own with mana value 3 or less.

Vigilance
When this Vehicle enters, you may search your library for an artifact card and reveal it. Put it onto the battlefield if its mana value is 2 or less. Otherwise, put it into your hand. If you search your library this way, shuffle.
Crew 2

This spell costs less to cast as long as you've drawn two or more cards this turn.
Flying, vigilance
Other Birds you control have vigilance.

Companion — Your starting deck contains only cards with even mana values. (If this card is your chosen companion, you may put it into your hand from outside the game for any time you could cast a sorcery.)
When Gyruda enters, each player mills four cards. Put a creature card with an even mana value from among the milled cards onto the battlefield under your control.

This spell costs less to cast for each creature you control with a +1/+1 counter on it.
Creature spells you cast cost less to cast for each creature you control with a +1/+1 counter on it.

Players can't gain life.
At the beginning of each player's upkeep, that player loses half their life, rounded up.

You have ten seconds to look at and rearrange the cards in your library. At the end of those ten seconds, if you're touching one or more of those cards, shuffle.

Creatures you control get +2/+2 and gain trample until end of turn. You may turn a creature you control face up.

Haste
Swampcycling , mountaincycling

Enchant creature
Enchanted creature gets +4/+4 and has first strike, and all creatures able to block it do so.
Umbra armor

When Indris, the Hydrostatic Surge enters, conjure a card named Lightning Bolt into your library. It perpetually gains storm. Then shuffle. Whenever you cast an instant or sorcery spell, draw a card.

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, destroy target non-Elf creature an opponent controls with power X or less, where X is the number of lands you control.