Zenith Chronicler

Whenever a player casts their first multicolored spell each turn, each other player draws a card.

Intellectual Offering

Choose an opponent. You and that player each draw three cards.
Choose an opponent. Untap all nonland permanents you control and all nonland permanents that player controls.

Sudden Substitution

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Exchange control of target noncreature spell and target creature. Then the spell's controller may choose new targets for it.

Kynaios and Tiro of Meletis

At the beginning of your end step, draw a card. Each player may put a land card from their hand onto the battlefield, then each opponent who didn't draws a card.

Reins of Power

Untap all creatures you control and all creatures target opponent controls. You and that opponent each gain control of all creatures the other controls until end of turn. Those creatures gain haste until end of turn.

Guided Passage

Reveal the cards in your library. An opponent chooses from among them a creature card, a land card, and a noncreature, nonland card. You put the chosen cards into your hand. Then shuffle.

Death by Dragons

Each player other than target player creates a 5/5 red Dragon creature token with flying.

Kaseto, Orochi Archmage

{G}{U}: Target creature can't be blocked this turn. If that creature is a Snake, it gets +2/+2 until end of turn.

Fractured Identity

Exile target nonland permanent. Each player other than its controller creates a token that's a copy of it.

Dubious Challenge

Look at the top ten cards of your library, exile up to two creature cards from among them, then shuffle. Target opponent may choose one of the exiled cards and put it onto the battlefield under their control. Put the rest onto the battlefield under your control.

Curse of Echoes

Enchant player
Whenever enchanted player casts an instant or sorcery spell, each other player may copy that spell and may choose new targets for the copy they control.

Humble Defector

{T}: Draw two cards. Target opponent gains control of Humble Defector. Activate only during your turn.