Arvinox, the Mind Flail isn't a creature unless you control three or more permanents you don't own.

At the beginning of your end step, exile the bottom card of each opponent's library face down. For as long as those cards remain exiled, you may look at them, you may cast permanent spells from among them, and you may spend mana as though it were mana of any color to cast those spells.

Devoid (This card has no color.)

Menace

Whenever Bismuth Mindrender deals combat damage to a player, that player exiles cards from the top of their library until they exile a nonland card. You may cast that card by paying life equal to the spell's mana value rather than paying its mana cost.

Target player shuffles their graveyard into their library.

Draw a card.

Shadow (This creature can block or be blocked by only creatures with shadow.)

Whenever Dauthi Mindripper attacks and isn't blocked, you may sacrifice it. If you do, defending player discards three cards.

Emerge (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)

When you cast this spell, target opponent reveals their hand. You choose from it a nonland card with mana value 3 or less and a card with mana value 4 or greater. That player discards those cards.

Enchant creature you control

Creatures you control have haste.

Flash

Flying

Whenever an opponent draws their second card each turn, you draw a card.

: Each player draws a card.

Search your library for an instant card with mana value 3, reveal it, and put it into your hand. Then repeat this process for instant cards with mana values 2 and 1. Then shuffle.

When Geralf's Mindcrusher enters, target player mills five cards.

Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

, , Discard two cards: Target player discards X cards at random.

Whenever a player casts an instant or sorcery spell, each other player copies that spell. Each of those players may choose new targets for their copy.

Reveal the top five cards of your library and separate them into two piles. An opponent chooses one of those piles. Put that pile into your hand and the other into your graveyard. Create a 0/0 colorless Thopter artifact creature token with flying, then put a +1/+1 counter on it for each card put into your graveyard this way.

+1: Draw a card.

+1: Untap all creatures you control.

−9: Gain control of up to three target creatures.

Compleated ( can be paid with or 2 life. If life was paid, this planeswalker enters with two fewer loyalty counters.)

+1: Until your next turn, up to one target creature gets -3/-0.

−2: Target player mills three cards. Then if a graveyard has twenty or more cards in it, you draw three cards. Otherwise, you draw a card.

−X: Target player mills three times X cards.

, : Choose target opponent who has at least two more cards in hand than you do as you activate this ability. Draw a card.

First strike, haste

Whenever Kellogg, Dangerous Mind attacks, create a Treasure token.

Sacrifice five Treasures: Gain control of target creature for as long as you control Kellogg. Activate only as a sorcery.

Hexproof

Whenever a creature card is put into an opponent's graveyard from anywhere, you may have Lazav, Dimir Mastermind become a copy of that card, except its name is Lazav, Dimir Mastermind, it's legendary in addition to its other types, and it has hexproof and this ability.

Whenever Mastermind Plum attacks, exile up to one target card from a graveyard. If an artifact card was exiled this way, create a Treasure token. (It's an artifact with ", Sacrifice this artifact: Add one mana of any color.")

Whenever you cast a spell, if mana from a Treasure was spent to cast it, you draw a card and you lose 1 life.

, Put a page counter on this artifact: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

, , Put a page counter on this artifact: Draw a card.

When there are four or more page counters on this artifact, exile it. If you do, you gain 4 life.

All creatures get -X/-0, where X is the number of cards in your hand.

Change the text of target permanent by replacing all instances of one color word with another or one basic land type with another. (For example, you may change "nonblack creature" to "nongreen creature" or "forestwalk" to "islandwalk." This effect lasts indefinitely.)

Target player discards X cards, where X is one plus the number of cards named Mind Burst in all graveyards.

Enchant creature

You control enchanted creature.

Threshold — As long as seven or more cards are in your graveyard, Mind Drill Assailant gets +3/+0.

: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Dominate Monster — When Mind Flayer enters, gain control of target creature for as long as you control Mind Flayer.

Buyback (You may pay an additional as you cast this spell. If you do, put this card into your hand as it resolves.)

Tap target artifact, creature, or land.

Enchant red or green creature

Cumulative upkeep (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

You control enchanted creature.

When Mind Maggots enters, discard any number of creature cards. For each card discarded this way, put two +1/+1 counters on Mind Maggots.

Buyback (You may pay an additional as you cast this spell. If you do, put this card into your hand as it resolves.)

Target player discards a card.

Devoid (This card has no color.)

When Mind Raker enters, you may put a card an opponent owns from exile into that player's graveyard. If you do, each opponent discards a card.

Target player discards two cards.

Target player discards X cards at random.

Target player discards a card for each Swamp you control.

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)

Target player draws three cards. If the gift was promised, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

: Add .

, , Sacrifice Mind Stone: Draw a card.

Target player discards X cards at random.

Look at target player's hand and choose X cards from it. That player discards those cards.

Defender (This creature can't attack.)

Flying

Whenever Mindbender Spores blocks a creature, put four fungus counters on that creature. The creature gains "This creature doesn't untap during your untap step if it has a fungus counter on it" and "At the beginning of your upkeep, remove a fungus counter from this creature."

Choose a nonland card name and a number greater than 0. Target player reveals their library. If that library contains exactly the chosen number of cards with the chosen name, Mindblaze deals 8 damage to that player. Then that player shuffles.

When Mindclaw Shaman enters, target opponent reveals their hand. You may cast an instant or sorcery spell from among those cards without paying its mana cost.

You draw two cards and target opponent discards two cards.

All Slivers have ", Sacrifice this permanent: Each player discards a card."

Trample

Whenever Mindleech Mass deals combat damage to a player, you may look at that player's hand. If you do, you may cast a spell from among those cards without paying its mana cost.

Mindless Automaton enters with two +1/+1 counters on it.

, Discard a card: Put a +1/+1 counter on Mindless Automaton.

Remove two +1/+1 counters from Mindless Automaton: Draw a card.

Mindless Null can't block unless you control a Vampire.

Players can't search libraries.

Whenever you cast a spell, put the cards in your hand on the bottom of your library in any order, then draw that many cards.

Join forces — Starting with you, each player may pay any amount of mana. Each player draws X cards, where X is the total amount of mana paid this way.

Whenever an opponent casts their first spell each turn, that player exiles the top card of their library. If it's a nonland card, you may cast it without paying its mana cost.

Flying

Whenever Mindscour Dragon deals combat damage to an opponent, target player mills four cards.