Theros

Battlewise Hoplite | Creature | Human Soldier | Heroic — Whenever you cast a spell that targets Battlewise Hoplite, put a +1/+1 counter on Battlewise Hoplite, then scry 1. (To scry 1, look at the top card of your library, then you may put that card on the bottom of your library.) | Willian Murai

Daxos of Meletis | Legendary Creature | Human Soldier | Daxos of Meletis can't be blocked by creatures with power 3 or greater. Whenever Daxos of Meletis deals combat damage to a player, exile the top card of that player's library. You gain life equal to that card's mana value. Until end of turn, you may cast that card and you may spend mana as though it were mana of any color to cast that spell. | Karla Ortiz

Medomai the Ageless | Legendary Creature | Sphinx | Flying Whenever Medomai the Ageless deals combat damage to a player, take an extra turn after this one. Medomai the Ageless can't attack during extra turns. | David Palumbo

Ashiok, Nightmare Weaver | Legendary Planeswalker | Ashiok | +2: Exile the top three cards of target opponent's library. −X: Put a creature card with mana value X exiled with Ashiok, Nightmare Weaver onto the battlefield under your control. That creature is a Nightmare in addition to its other types. −10: Exile all cards from all opponents' hands and graveyards. | Karla Ortiz

Psychic Intrusion | Sorcery | | Target opponent reveals their hand. You choose a nonland card from that player's graveyard or hand and exile it. You may cast that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell. | Jaime Jones

Shipwreck Singer | Creature | Siren | Flying {1}{U}: Target creature an opponent controls attacks this turn if able. {1}{B}, {T}: Attacking creatures get -1/-1 until end of turn. | Daarken

Spellheart Chimera | Creature | Chimera | Flying, trample Spellheart Chimera's power is equal to the number of instant and sorcery cards in your graveyard. | Svetlin Velinov

Steam Augury | Instant | | Reveal the top five cards of your library and separate them into two piles. An opponent chooses one of those piles. Put that pile into your hand and the other into your graveyard. | Dave Kendall

Horizon Chimera | Creature | Chimera | Flash Flying, trample Whenever you draw a card, you gain 1 life. | Sam Burley

Prophet of Kruphix | Creature | Human Wizard | Untap all creatures and lands you control during each other player's untap step. You may cast creature spells as though they had flash. | Winona Nelson