Foundations

Curator of Destinies | Creature | Sphinx | This spell can't be countered. Flying When this creature enters, look at the top five cards of your library and separate them into a face-down pile and a face-up pile. An opponent chooses one of those piles. Put that pile into your hand and the other into your graveyard. | Ralph Horsley

Grappling Kraken | Creature | Kraken | Landfall — Whenever a land you control enters, 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.) | Ben Wootten

Extravagant Replication | Enchantment | | At the beginning of your upkeep, create a token that's a copy of another target nonland permanent you control. | Pauline Voss

Self-Reflection | Sorcery | | Create a token that's a copy of target creature you control. Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.) | Henry Peters

Time Stop | Instant | | End the turn. (Exile all spells and abilities from the stack, including this card. The player whose turn it is discards down to their maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.) | Scott M. Fischer

Confiscate | Enchantment | Aura | Enchant permanent You control enchanted permanent. | Caroline Gariba

Arcanis the Omnipotent | Legendary Creature | Wizard | {T}: Draw three cards. {2}{U}{U}: Return Arcanis to its owner's hand. | Justin Sweet

Niv-Mizzet, Visionary | Legendary Creature | Dragon Wizard | Flying You have no maximum hand size. Whenever a source you control deals noncombat damage to an opponent, you draw that many cards. | Dan Murayama Scott

Thousand-Year Storm | Enchantment | | Whenever you cast an instant or sorcery spell, copy it for each other instant and sorcery spell you've cast before it this turn. You may choose new targets for the copies. | Dimitar Marinski

Muldrotha, the Gravetide | Legendary Creature | Elemental Avatar | During each of your turns, you may play a land and cast a permanent spell of each permanent type from your graveyard. (If a card has multiple permanent types, choose one as you play it.) | Jason Rainville