Arm with Aether

Until end of turn, creatures you control gain "Whenever this creature deals damage to an opponent, you may return target creature that player controls to its owner's hand."

Battle-Rage Blessing

Target creature gains deathtouch and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Maze Glider

Flying
Multicolored creatures you control have flying.

Atarka Pummeler

Formidable — {3}{R}{R}: Creatures you control gain menace until end of turn. Activate only if creatures you control have total power 8 or greater. (They can't be blocked except by two or more creatures.)

Thassa's Ire

{3}{U}: You may tap or untap target creature.

Dragonmaster Outcast

At the beginning of your upkeep, if you control six or more lands, create a 5/5 red Dragon creature token with flying.

Manifold Key

{1}, {T}: Untap another target artifact.
{3}, {T}: Target creature can't be blocked this turn.

Amber Prison

You may choose not to untap Amber Prison during your untap step.
{4}, {T}: Tap target artifact, creature, or land. That permanent doesn't untap during its controller's untap step for as long as Amber Prison remains tapped.

Lux Cannon

{T}: Put a charge counter on Lux Cannon.
{T}, Remove three charge counters from Lux Cannon: Destroy target permanent.

Blustersquall

Tap target creature you don't control.
Overload {3}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Crash Through

Creatures you control gain trample until end of turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)
Draw a card.

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Paradox Haze

Enchant player
At the beginning of enchanted player's first upkeep each turn, that player gets an additional upkeep step after this step.

Festering Wound

Enchant creature
At the beginning of your upkeep, you may put an infection counter on Festering Wound.
At the beginning of the upkeep of enchanted creature's controller, Festering Wound deals X damage to that player, where X is the number of infection counters on Festering Wound.

Obeka, Splitter of Seconds

Menace
Whenever Obeka, Splitter of Seconds deals combat damage to a player, you get that many additional upkeep steps after this phase.

Crumbling Necropolis

Crumbling Necropolis enters the battlefield tapped.
{T}: Add {U}, {B}, or {R}.

Burst of Speed

Creatures you control gain haste until end of turn. (They can attack and {T} even if they just came under your control.)

Coralhelm Guide

{4}{U}: Target creature can't be blocked this turn.

Library of Leng

You have no maximum hand size.
If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.

Cleaver Riot

Creatures you control gain double strike until end of turn. (They deal both first-strike and regular combat damage.)

Chariot of Victory

Equipped creature has first strike, trample, and haste.
Equip {1}

Dream's Grip

Choose one —
• Tap target permanent.
• Untap target permanent.
Entwine {1} (Choose both if you pay the entwine cost.)

The Immortal Sun

Players can't activate planeswalkers' loyalty abilities.
At the beginning of your draw step, draw an additional card.
Spells you cast cost {1} less to cast.
Creatures you control get +1/+1.

Venser's Journal

You have no maximum hand size.
At the beginning of your upkeep, you gain 1 life for each card in your hand.

Maze Rusher

Haste
Multicolored creatures you control have haste.

Suspicious Bookcase

Defender
{3}, {T}: Target creature can't be blocked this turn.

Akki Drillmaster

{T}: Target creature gains haste until end of turn.

Burning Anger

Enchant creature
Enchanted creature has "{T}: This creature deals damage equal to its power to any target."

Emberwilde Augur

Sacrifice Emberwilde Augur: It deals 3 damage to target player or planeswalker. Activate only during your upkeep.

Amphin Pathmage

{2}{U}: Target creature can't be blocked this turn.

Vela the Night-Clad

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Other creatures you control have intimidate.
Whenever Vela the Night-Clad or another creature you control leaves the battlefield, each opponent loses 1 life.

Island

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Flood

{U}{U}: Tap target creature without flying.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters the battlefield with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Ring of Valkas

Equipped creature has haste. (It can attack and {T} no matter when it came under your control.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's red.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Embercleave

Flash
This spell costs {1} less to cast for each attacking creature you control.
When Embercleave enters the battlefield, attach it to target creature you control.
Equipped creature gets +1/+1 and has double strike and trample.
Equip {3}

Ethereal Usher

{U}, {T}: Target creature can't be blocked this turn.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Aether Vial

At the beginning of your upkeep, you may put a charge counter on Aether Vial.
{T}: You may put a creature card with mana value equal to the number of charge counters on Aether Vial from your hand onto the battlefield.

Maze Abomination

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Multicolored creatures you control have deathtouch.

Creeping Bloodsucker

At the beginning of your upkeep, Creeping Bloodsucker deals 1 damage to each opponent. You gain life equal to the damage dealt this way.

Incendiary

Enchant creature
At the beginning of your upkeep, you may put a fuse counter on Incendiary.
When enchanted creature dies, Incendiary deals X damage to any target, where X is the number of fuse counters on Incendiary.

Sol Ring

Swamp

Soured Springs

Soured Springs enters the battlefield tapped.
When Soured Springs enters the battlefield, it deals 1 damage to target opponent.
{T}: Add {U} or {B}.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Krydle of Baldur's Gate

Whenever Krydle of Baldur's Gate deals combat damage to a player, that player loses 1 life and mills a card, then you gain 1 life and scry 1.
Whenever you attack, you may pay {2}. If you do, target creature can't be blocked this turn.

Stigma Lasher

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever Stigma Lasher deals damage to a player, that player can't gain life for the rest of the game.

The Ninth Doctor

Haste
Into the TARDIS — Whenever The Ninth Doctor becomes untapped during your untap step, you get an additional upkeep step after this step.

Rathi Trapper

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Assault Strobe

Target creature gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Hithlain Knots

Tap target creature. Scry 1.
Draw a card.

Eroded Canyon

Eroded Canyon enters the battlefield tapped.
When Eroded Canyon enters the battlefield, it deals 1 damage to target opponent.
{T}: Add {U} or {R}.

Fiendlash

Equipped creature gets +2/+0 and has reach.
Whenever equipped creature is dealt damage, it deals damage equal to its power to target player or planeswalker.
Equip {2}{R}

As Foretold

At the beginning of your upkeep, put a time counter on As Foretold.
Once each turn, you may pay {0} rather than pay the mana cost for a spell you cast with mana value X or less, where X is the number of time counters on As Foretold.

Jagged Barrens

Jagged Barrens enters the battlefield tapped.
When Jagged Barrens enters the battlefield, it deals 1 damage to target opponent.
{T}: Add {B} or {R}.

Dragon

Ghastly Death Tyrant

When Ghastly Death Tyrant enters the battlefield, choose one —
• Disintegration Ray — Destroy target enchantment an opponent controls. You lose life equal to its mana value.
• Death Ray — Creatures you control gain deathtouch until end of turn.

Golden Urn

At the beginning of your upkeep, you may put a charge counter on Golden Urn.
{T}, Sacrifice Golden Urn: You gain life equal to the number of charge counters on Golden Urn.

Infiltrate

Target creature can't be blocked this turn.

Legacy's Allure

At the beginning of your upkeep, you may put a treasure counter on Legacy's Allure.
Sacrifice Legacy's Allure: Gain control of target creature with power less than or equal to the number of treasure counters on Legacy's Allure. (This effect lasts indefinitely.)

Frostwind Invoker

Flying
{8}: Creatures you control gain flying until end of turn.

Portal to Phyrexia

When Portal to Phyrexia enters the battlefield, each opponent sacrifices three creatures.
At the beginning of your upkeep, put target creature card from a graveyard onto the battlefield under your control. It's a Phyrexian in addition to its other types.

Air Servant

Flying
{2}{U}: Tap target creature with flying.

Stalking Vengeance

Haste
Whenever another creature you control dies, it deals damage equal to its power to target player or planeswalker.

Mountain

Artful Dodge

Target creature can't be blocked this turn.
Flashback {U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Augur of Skulls

{1}{B}: Regenerate Augur of Skulls.
Sacrifice Augur of Skulls: Target player discards two cards. Activate only during your upkeep.

Key to the City

{T}, Discard a card: Up to one target creature can't be blocked this turn.
Whenever Key to the City becomes untapped, you may pay {2}. If you do, draw a card.

Fountain of Renewal

At the beginning of your upkeep, you gain 1 life.
{3}, Sacrifice Fountain of Renewal: Draw a card.