Assassin

Whenever this creature deals combat damage to a player, that player loses the game.

Kraken

Jace, Unraveler of Secrets Emblem

Whenever an opponent casts their first spell each turn, counter that spell.

Teferi, Hero of Dominaria Emblem

Whenever you draw a card, exile target permanent an opponent controls.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Tamiyo, Field Researcher Emblem

You may cast nonland cards from your hand without paying their mana costs.

Elspeth, Sun's Champion Emblem

Creatures you control get +2/+2 and have flying.

Interplanar Beacon

Whenever you cast a planeswalker spell, you gain 1 life.
{T}: Add {C}.
{1}, {T}: Add two mana of different colors. Spend this mana only to cast planeswalker spells.

Narset Transcendent Emblem

Your opponents can't cast noncreature spells.

Kaya the Inexorable Emblem

At the beginning of your upkeep, you may cast a legendary spell from your hand, from your graveyard, or from among cards you own in exile without paying its mana cost.

Marsh Flats

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Teferi, Temporal Archmage Emblem

You may activate loyalty abilities of planeswalkers you control on any player's turn any time you could cast an instant.

Teferi, Who Slows the Sunset Emblem

Untap all permanents you control during each opponent's untap step.
You draw a card during each opponent's draw step.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Kiora, the Crashing Wave Emblem

At the beginning of your end step, create a 9/9 blue Kraken creature token.

Tamiyo, the Moon Sage Emblem

You have no maximum hand size.
Whenever a card is put into your graveyard from anywhere, you may return it to your hand.