Ikoria: Lair of Behemoths

Mythos of Snapdax | Sorcery | | Each player chooses an artifact, a creature, an enchantment, and a planeswalker from among the nonland permanents they control, then sacrifices the rest. If {B}{R} was spent to cast this spell, you choose the permanents for each player instead. | Seb McKinnon

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

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

Savai Triome | Land | Mountain Plains Swamp | ({T}: Add {R}, {W}, or {B}.) Savai Triome enters the battlefield tapped. Cycling {3} ({3}, Discard this card: Draw a card.) | Titus Lunter