Tiamat

Flying
When Tiamat enters, if you cast it, search your library for up to five Dragon cards not named Tiamat that each have different names, reveal them, put them into your hand, then shuffle.

Monk of the Open Hand

Flurry of Blows — Whenever you cast your second spell each turn, put a +1/+1 counter on this creature.

Octopus Umbra

Enchant creature
Enchanted creature has base power and toughness 8/8 and has "Whenever this creature attacks, you may tap target creature with power 8 or less."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Tiamat's Fanatics

Haste
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Unraveling Mummy

{1}{W}: Target attacking Zombie gains lifelink until end of turn.
{1}{B}: Target attacking Zombie gains deathtouch until end of turn.

Everlasting Torment

Players can't gain life.
Damage can't be prevented.
All damage is dealt as though its source had wither. (A source with wither deals damage to creatures in the form of -1/-1 counters.)

Sparring Mummy

When this creature enters, untap target creature.

Massacre Girl, Known Killer

Menace
Creatures you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent controls dies, if its toughness was less than 1, draw a card.

Monk Class

(Gain the next level as a sorcery to add its ability.)
The second spell you cast each turn costs {1} less to cast.
{W}{U}: Level 2
When this Class becomes level 2, return up to one target nonland permanent to its owner's hand.
{1}{W}{U}: Level 3
At the beginning of your upkeep, exile the top card of your library. For as long as it remains exiled, it has "You may cast this card from exile as long as you've cast another spell this turn."

Temple Acolyte

When this creature enters, you gain 3 life.

City of Brass

Whenever this land becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Fylamarid

Flying
This creature can't be blocked by blue creatures.
{U}: Target creature becomes blue until end of turn.

Bag of Holding

Whenever you discard a card, exile that card from your graveyard.
{2}, {T}: Draw a card, then discard a card.
{4}, {T}, Sacrifice this artifact: Return all cards exiled with this artifact to their owner's hand.

Half-Elf Monk

Vigilance
Stunning Strike — {1}{W}, {T}: Tap target creature.

Elder Druid

{3}{G}, {T}: You may tap or untap target artifact, creature, or land.

Up the Beanstalk

When this enchantment enters and whenever you cast a spell with mana value 5 or greater, draw a card.

Selvala, Heart of the Wilds

Whenever another creature enters, its controller may draw a card if its power is greater than each other creature's power.
{G}, {T}: Add X mana in any combination of colors, where X is the greatest power among creatures you control.

Fade Away

For each creature, its controller sacrifices a permanent of their choice unless they pay {1}.

Bennie Bracks, Zoologist

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
At the beginning of each end step, if you created a token this turn, draw a card.

Blue Dragon

Flying
Lightning Breath — When this creature enters, until your next turn, target creature an opponent controls gets -3/-0, up to one other target creature gets -2/-0, and up to one other target creature gets -1/-0.

Tall as a Beanstalk

Enchant creature
Enchanted creature gets +3/+3, has reach, and is a Giant in addition to its other types.

Temple of the Dragon Queen

As this land enters, you may reveal a Dragon card from your hand. This land enters tapped unless you revealed a Dragon card this way or you control a Dragon.
As this land enters, choose a color.
{T}: Add one mana of the chosen color.

Narset, Enlightened Exile

Creatures you control have prowess.
Whenever Narset attacks, exile target noncreature, nonland card with mana value less than Narset's power from a graveyard and copy it. You may cast the copy without paying its mana cost.

Raging Gorilla

Whenever this creature blocks or becomes blocked, it gets +2/-2 until end of turn.

Withering Gaze

Target opponent reveals their hand. You draw a card for each Forest and green card in it.