Zellix, Sanity Flayer

Hive Mind — Whenever a player mills one or more creature cards, you create a 1/1 black Horror creature token.
{1}, {T}: Target player mills three cards.
Choose a Background (You can have a Background as a second commander.)

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Silent Hallcreeper

Silent Hallcreeper can't be blocked.
Whenever Silent Hallcreeper deals combat damage to a player, choose one that hasn't been chosen —
• Put two +1/+1 counters on Silent Hallcreeper.
• Draw a card.
• Silent Hallcreeper becomes a copy of another target creature you control.

Fog Bank

Defender, flying
Prevent all combat damage that would be dealt to and dealt by Fog Bank.

Shadow Kin

Flash
At the beginning of your upkeep, each player mills three cards. You may exile a creature card from among the cards milled this way. If you do, Shadow Kin becomes a copy of that card, except it has this ability.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Vantress Gargoyle

Flying
Vantress Gargoyle can't attack unless defending player has seven or more cards in their graveyard.
Vantress Gargoyle can't block unless you have four or more cards in hand.
{T}: Each player mills a card.

Reliquary Tower

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

Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.

Mockingbird

Flying
You may have Mockingbird enter as a copy of any creature on the battlefield with mana value less than or equal to the amount of mana spent to cast Mockingbird, except it's a Bird in addition to its other types and it has flying.

The Mindskinner

The Mindskinner can't be blocked.
If a source you control would deal damage to an opponent, prevent that damage and each opponent mills that many cards.

Riddlekeeper

Whenever a creature attacks you or a planeswalker you control, that creature's controller mills two cards.

Tempest Djinn

Flying
Tempest Djinn gets +1/+0 for each basic Island you control.

Counterspell

Mirelurk Queen

Vigilance
When Mirelurk Queen enters, target player gets two rad counters.
Whenever one or more nonland cards are milled, draw a card, then put a +1/+1 counter on Mirelurk Queen. This ability triggers only once each turn.

Tasha's Hideous Laughter

Each opponent exiles cards from the top of their library until that player has exiled cards with total mana value 20 or more.

Spark Double

You may have Spark Double enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Manic Scribe

When Manic Scribe enters, each opponent mills three cards.
Delirium — At the beginning of each opponent's upkeep, if there are four or more card types among cards in your graveyard, that player mills three cards.

Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Eluge, the Shoreless Sea

Eluge's power and toughness are each equal to the number of Islands you control.
Whenever Eluge enters or attacks, put a flood counter on target land. It's an Island in addition to its other types for as long as it has a flood counter on it.
The first instant or sorcery spell you cast each turn costs {U} (or {1}) less to cast for each land you control with a flood counter on it.

Slither Blade

Unable to Scream

Enchant creature
Enchanted creature loses all abilities and is a Toy artifact creature with base power and toughness 0/2 in addition to its other types.
As long as enchanted creature is face down, it can't be turned face up.

Soulless Jailer

Permanent cards in graveyards can't enter the battlefield.
Players can't cast noncreature spells from graveyards or exile.

Harbinger of the Seas

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Bruvac the Grandiloquent

If an opponent would mill one or more cards, they mill twice that many cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Giggling Skitterspike

Indestructible
Whenever Giggling Skitterspike attacks, blocks, or becomes the target of a spell, it deals damage equal to its power to each opponent.
{5}: Monstrosity 5. (If this creature isn't monstrous, put five +1/+1 counters on it and it becomes monstrous.)

Relic Golem

Relic Golem can't attack or block unless an opponent has eight or more cards in their graveyard.
{2}, {T}: Target player mills two cards. (They put the top two cards of their library into their graveyard.)

Terisian Mindbreaker

Whenever Terisian Mindbreaker attacks, defending player mills half their library, rounded up.
Unearth {1}{U}{U}{U} ({1}{U}{U}{U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Hunted Phantasm

Hunted Phantasm can't be blocked.
When Hunted Phantasm enters, target opponent creates five 1/1 red Goblin creature tokens.

Sapphire Medallion

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

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Canoptek Scarab Swarm

Flying
Feeder Mandibles — When Canoptek Scarab Swarm enters, exile target player's graveyard. For each artifact or land card exiled this way, create a 1/1 colorless Insect artifact creature token with flying.