Ikoria: Lair of Behemoths

Lurrus of the Dream-Den | Legendary Creature | Cat Nightmare | Companion — Each permanent card in your starting deck has mana value 2 or less. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} any time you could cast a sorcery.) Lifelink During each of your turns, you may cast one permanent spell with mana value 2 or less from your graveyard. | Slawomir Maniak

Slitherwisp | Creature | Elemental Nightmare | Flash Whenever you cast another spell that has flash, you draw a card and each opponent loses 1 life. | Yigit Koroglu

Gyruda, Doom of Depths | Legendary Creature | Demon Kraken | Companion — Your starting deck contains only cards with even mana values. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} any time you could cast a sorcery.) When Gyruda enters the battlefield, each player mills four cards. Put a creature card with an even mana value from among the milled cards onto the battlefield under your control. | Tyler Jacobson

Labyrinth Raptor | Creature | Nightmare Dinosaur | Menace Whenever a creature you control with menace becomes blocked, defending player sacrifices a creature blocking it. {B}{R}: Creatures you control with menace get +1/+0 until end of turn. | Daarken

Obosh, the Preypiercer | Legendary Creature | Hellion Horror | Companion — Your starting deck contains only cards with odd mana values and land cards. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} any time you could cast a sorcery.) If a source you control with an odd mana value would deal damage to a permanent or player, it deals double that damage to that permanent or player instead. | Daarken

Umori, the Collector | Legendary Creature | Ooze | Companion — Each nonland card in your starting deck shares a card type. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} any time you could cast a sorcery.) As Umori, the Collector enters the battlefield, choose a card type. Spells you cast of the chosen type cost {1} less to cast. | Jehan Choo

Jegantha, the Wellspring | Legendary Creature | Elemental Elk | Companion — No card in your starting deck has more than one of the same mana symbol in its mana cost. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} any time you could cast a sorcery.) {T}: Add {W}{U}{B}{R}{G}. This mana can't be spent to pay generic mana costs. | Chris Rahn

Offspring's Revenge | Enchantment | | At the beginning of combat on your turn, exile target red, white, or black creature card from your graveyard. Create a token that's a copy of that card, except it's 1/1. It gains haste until your next turn. | Daarken

Ruinous Ultimatum | Sorcery | | Destroy all nonland permanents your opponents control. | Chase Stone

Death's Oasis | Enchantment | | Whenever a nontoken creature you control dies, mill two cards. Then return a creature card with lesser mana value than the creature that died from your graveyard to your hand. {1}, Sacrifice Death's Oasis: You gain life equal to the highest mana value among creatures you control. | Grzegorz Rutkowski

Eerie Ultimatum | Sorcery | | Return any number of permanent cards with different names from your graveyard to the battlefield. | Jason A. Engle

Emergent Ultimatum | Sorcery | | Search your library for up to three monocolored cards with different names and exile them. An opponent chooses one of those cards. Shuffle that card into your library. You may cast the other cards without paying their mana costs. Exile Emergent Ultimatum. | Zack Stella

Titans' Nest | Enchantment | | At the beginning of your upkeep, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.) Exile a card from your graveyard: Add {C}. Spend this mana only to cast a spell that's one or more colors without {X} in its mana cost. | Cliff Childs