Leela, Sevateem Warrior

Whenever an opponent draws a card except the first one they draw in each of their draw steps, put a +1/+1 counter on Leela, Sevateem Warrior.
Doctor's companion (You can have two commanders if the other is the Doctor.)

The Second Doctor

Players have no maximum hand size.
How Civil of You — At the beginning of your end step, each player may draw a card. Each opponent who does can't attack you or permanents you control during their next turn.

Island

Plains

Forest

Counterspell

Negate

Thieving Skydiver

Kicker {X}. X can't be 0. (You may pay an additional {X} as you cast this spell.)
Flying
When Thieving Skydiver enters, if it was kicked, gain control of target artifact with mana value X or less. If that artifact is an Equipment, attach it to Thieving Skydiver.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Mindbreak Trap

If an opponent cast three or more spells this turn, you may pay {0} rather than pay this spell's mana cost.
Exile any number of target spells.

Smirking Spelljacker

Flash
Flying
When Smirking Spelljacker enters, exile target spell an opponent controls.
Whenever Smirking Spelljacker attacks, if a card is exiled with it, you may cast the exiled card without paying its mana cost.

Absorb

Archmage's Charm

Choose one —
• Counter target spell.
• Target player draws two cards.
• Gain control of target nonland permanent with mana value 1 or less.

Teferi, Mage of Zhalfir

Flash
Creature cards you own that aren't on the battlefield have flash.
Each opponent can cast spells only any time they could cast a sorcery.

Vedalken Orrery

You may cast spells as though they had flash.

Barkhide Troll

Barkhide Troll enters with a +1/+1 counter on it.
{1}, Remove a +1/+1 counter from Barkhide Troll: Barkhide Troll gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Bone to Ash

Counter target creature spell.
Draw a card.

Cancel

Clash of Wills

Counter target spell unless its controller pays {X}.

Counterlash

Counter target spell. You may cast a spell that shares a card type with it from your hand without paying its mana cost.

Decisive Denial

Choose one —
• Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)
• Counter target noncreature spell unless its controller pays {3}.

Desertion

Counter target spell. If an artifact or creature spell is countered this way, put that card onto the battlefield under your control instead of into its owner's graveyard.

Didn't Say Please

Counter target spell. Its controller mills three cards.

Elder Owyn Lyons

Artifacts you control have ward {1}. (Whenever an artifact you control becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
When Elder Owyn Lyons enters or dies, return target artifact card from your graveyard to your hand.

Fall of the Gavel

Kami of Whispered Hopes

If one or more +1/+1 counters would be put on a permanent you control, that many plus one +1/+1 counters are put on that permanent instead.
{T}: Add X mana of any one color, where X is Kami of Whispered Hopes's power.

Frilled Mystic

Flash
When Frilled Mystic enters, you may counter target spell.

Plasm Capture

Counter target spell. At the beginning of your next first main phase, add X mana in any combination of colors, where X is that spell's mana value.

Mystic Snake

Flash
When Mystic Snake enters, counter target spell.

Voidslime

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Mystic Genesis

Counter target spell. Create an X/X green Ooze creature token, where X is that spell's mana value.

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Hindering Light

Counter target spell that targets you or a permanent you control.
Draw a card.

Aven Mindcensor

Flash
Flying
If an opponent would search a library, that player searches the top four cards of that library instead.