As an additional cost to cast this spell, sacrifice X lands.
Create two X/X red Elemental creature tokens.

Flash
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for or one mana of that creature's color.)
Double strike
Other tapped creatures you control have hexproof.

Menace
Whenever this creature deals combat damage to a player, if it has fewer than four +1/+1 counters on it, put a +1/+1 counter on it. Then if it has exactly four +1/+1 counters on it, search your library for a card, put it into your hand, then shuffle.

+1: You draw a card and you lose 1 life.
−3: Destroy target creature.
−8: Target opponent gets an emblem with "Whenever a player draws a card, you lose 2 life."

Flying
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
At the beginning of combat on your turn, choose up to one target creature you control. Until end of turn, that creature gets +2/+0, gains trample if it's red, and gains vigilance if it's white.

This land enters tapped unless you control a Plains or an Island.
: Add or .

Whenever another creature or artifact you control enters, this creature deals 1 damage to each opponent.
Warp (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Destroy target non-outlaw creature. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws. Everyone else is fair game.)

+1: Create a 1/1 white Kor Warrior creature token. You may attach an Equipment you control to it.
−2: Look at the top six cards of your library. You may reveal a Warrior or Equipment card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
−3: Nahiri deals damage to target creature or planeswalker equal to twice the number of Equipment you control.

Return target creature to its owner's hand. Untap up to two lands.

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for or one mana of that creature's color.)
Choose a creature type. Return all creature cards of the chosen type from your graveyard to the battlefield.

: Add .
: Add or . This artifact deals 1 damage to you.

Legendary creatures you control get +X/+X, where X is the number of legendary creatures you control.
Whenever you cast a legendary spell from your hand, exile cards from the top of your library until you exile a legendary nonland card with lesser mana value. You may cast that card without paying its mana cost. Put the rest on the bottom of your library in a random order.

At the beginning of each player's upkeep, that player chooses target player who controls more creatures than they do and is their opponent. The first player may reveal cards from the top of their library until they reveal a creature card. If the first player does, that player puts that card onto the battlefield and all other cards revealed this way into their graveyard.

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Menace, toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Vishgraz enters, create three 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This token can't block."
Vishgraz gets +1/+1 for each poison counter your opponents have.

Destroy target creature, enchantment, or planeswalker. Its controller creates two Map tokens. (They're artifacts with ", , Sacrifice this token: Target creature you control explores. Activate only as a sorcery.")

Constellation — Whenever an enchantment you control enters, put a +1/+1 counter on this creature and draw a card.

This spell costs less to cast, where X is the greatest mana value among Elementals you control.
Flying
When this creature enters, if you cast it, return all non-Elemental creatures to their owners' hands.