Scalelord Reckoner

Flying
Whenever a Dragon you control becomes the target of a spell or ability an opponent controls, destroy target nonland permanent that player controls.

Sarkhan Unbroken

+1: Draw a card, then add one mana of any color.
−2: Create a 4/4 red Dragon creature token with flying.
−8: Search your library for any number of Dragon creature cards, put them onto the battlefield, then shuffle.

Kiora, Master of the Depths

+1: Untap up to one target creature and up to one target land.
−2: Reveal the top four cards of your library. You may put a creature card and/or a land card from among them into your hand. Put the rest into your graveyard.
−8: You get an emblem with "Whenever a creature you control enters, you may have it fight target creature." Then create three 8/8 blue Octopus creature tokens.

Living End

Suspend 3—{2}{B}{B}
Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Pearl Medallion

White spells you cast cost {1} less to cast.

Grim Hireling

Whenever one or more creatures you control deal combat damage to a player, create two Treasure tokens.
{B}, Sacrifice X Treasures: Target creature gets -X/-X until end of turn. Activate only as a sorcery.

Secure the Wastes

Create X 1/1 white Warrior creature tokens.

Edgar Markov

Eminence — Whenever you cast another Vampire spell, if Edgar Markov is in the command zone or on the battlefield, create a 1/1 black Vampire creature token.
First strike, haste
Whenever Edgar Markov attacks, put a +1/+1 counter on each Vampire you control.

Utvara Hellkite

Flying
Whenever a Dragon you control attacks, create a 6/6 red Dragon creature token with flying.

Sakashima the Impostor

You may have Sakashima the Impostor enter as a copy of any creature on the battlefield, except its name is Sakashima the Impostor, it's legendary in addition to its other types, and it has "{2}{U}{U}: Return this creature to its owner's hand at the beginning of the next end step."

The Ur-Dragon

Eminence — As long as The Ur-Dragon is in the command zone or on the battlefield, other Dragon spells you cast cost {1} less to cast.
Flying
Whenever one or more Dragons you control attack, draw that many cards, then you may put a permanent card from your hand onto the battlefield.

Rotlung Reanimator

Whenever Rotlung Reanimator or another Cleric dies, create a 2/2 black Zombie creature token.

Kindred Charge

Choose a creature type. For each creature you control of the chosen type, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Green Sun's Zenith

Search your library for a green creature card with mana value X or less, put it onto the battlefield, then shuffle. Shuffle Green Sun's Zenith into its owner's library.

Recurring Nightmare

Sacrifice a creature, Return Recurring Nightmare to its owner's hand: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

Oloro, Ageless Ascetic

At the beginning of your upkeep, you gain 2 life.
Whenever you gain life, you may pay {1}. If you do, draw a card and each opponent loses 1 life.
At the beginning of your upkeep, if Oloro, Ageless Ascetic is in the command zone, you gain 2 life.

Time Warp

Target player takes an extra turn after this one.

Darksteel Forge

Artifacts you control have indestructible. (Effects that say "destroy" don't destroy them. Artifact creatures with indestructible can't be destroyed by damage.)

Transcendence

You don't lose the game for having 0 or less life.
When you have 20 or more life, you lose the game.
Whenever you lose life, you gain 2 life for each 1 life you lost. (Damage dealt to you causes you to lose life.)

Door of Destinies

As Door of Destinies enters, 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.

Inexorable Tide

Whenever you cast a spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Narset Transcendent

+1: Look at the top card of your library. If it's a noncreature, nonland card, you may reveal it and put it into your hand.
−2: When you next cast an instant or sorcery spell from your hand this turn, it gains rebound. (Exile the spell as it resolves. At the beginning of your next upkeep, you may cast that card from exile without paying its mana cost.)
−9: You get an emblem with "Your opponents can't cast noncreature spells."

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.

Scion of the Ur-Dragon

Flying
{2}: Search your library for a Dragon permanent card and put it into your graveyard. If you do, Scion of the Ur-Dragon becomes a copy of that card until end of turn. Then shuffle.

Deadeye Navigator

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Deadeye Navigator is paired with another creature, each of those creatures has "{1}{U}: Exile this creature, then return it to the battlefield under your control."

Thalia's Lieutenant

When Thalia's Lieutenant enters, put a +1/+1 counter on each other Human you control.
Whenever another Human you control enters, put a +1/+1 counter on Thalia's Lieutenant.