Battlefield Thaumaturge | Creature | Human Wizard | Each instant and sorcery spell you cast costs {1} less to cast for each creature it targets.
Heroic — Whenever you cast a spell that targets Battlefield Thaumaturge, Battlefield Thaumaturge gains hexproof until end of turn. | Mike Sass
Cloaked Siren | Creature | Siren | Flash (You may cast this spell any time you could cast an instant.)
Flying | Mark Zug
Crystalline Nautilus | Enchantment Creature | Nautilus | Bestow {3}{U}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
When Crystalline Nautilus becomes the target of a spell or ability, sacrifice it.
Enchanted creature gets +4/+4 and has "When this creature becomes the target of a spell or ability, sacrifice it." | Brad Rigney
Dakra Mystic | Creature | Merfolk Wizard | {U}, {T}: Each player reveals the top card of their library. You may put the revealed cards into their owners' graveyards. If you don't, each player draws a card. | Wesley Burt
Daring Thief | Creature | Human Rogue | Inspired — Whenever Daring Thief becomes untapped, you may exchange control of target nonland permanent you control and target permanent an opponent controls that shares a card type with it. | Johann Bodin
Godhunter Octopus | Creature | Octopus | Godhunter Octopus can't attack unless defending player controls an enchantment or an enchanted permanent. | Tyler Jacobson
Hypnotic Siren | Enchantment Creature | Siren | Bestow {5}{U}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying
You control enchanted creature.
Enchanted creature gets +1/+1 and has flying. | James Ryman
Riptide Chimera | Enchantment Creature | Chimera | Flying
At the beginning of your upkeep, return an enchantment you control to its owner's hand. | Ryan Barger
Sage of Hours | Creature | Human Wizard | Heroic — Whenever you cast a spell that targets Sage of Hours, put a +1/+1 counter on it.
Remove all +1/+1 counters from Sage of Hours: For each five counters removed this way, take an extra turn after this one. | Matt Stewart
Scourge of Fleets | Creature | Kraken | When Scourge of Fleets enters the battlefield, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control. | Steven Belledin
Sigiled Starfish | Creature | Starfish | {T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.) | Nils Hamm
Thassa's Devourer | Enchantment Creature | Elemental | Constellation — Whenever Thassa's Devourer or another enchantment enters the battlefield under your control, target player mills two cards. | David Palumbo
Triton Cavalry | Creature | Merfolk Soldier | Heroic — Whenever you cast a spell that targets Triton Cavalry, you may return target enchantment to its owner's hand. | Kev Walker
Triton Shorestalker | Creature | Merfolk Rogue | Triton Shorestalker can't be blocked. | Svetlin Velinov
War-Wing Siren | Creature | Siren Soldier | Flying
Heroic — Whenever you cast a spell that targets War-Wing Siren, put a +1/+1 counter on War-Wing Siren. | Magali Villeneuve
Whitewater Naiads | Enchantment Creature | Nymph | Constellation — Whenever Whitewater Naiads or another enchantment enters the battlefield under your control, target creature can't be blocked this turn. | William Wu
Disciple of Deceit | Creature | Human Rogue | Inspired — Whenever Disciple of Deceit becomes untapped, you may discard a nonland card. If you do, search your library for a card with the same mana value as that card, reveal it, put it into your hand, then shuffle. | Daarken
Keranos, God of Storms | Legendary Enchantment Creature | God | Indestructible
As long as your devotion to blue and red is less than seven, Keranos isn't a creature.
Reveal the first card you draw on each of your turns. Whenever you reveal a land card this way, draw a card. Whenever you reveal a nonland card this way, Keranos deals 3 damage to any target. | Daarken
Stormchaser Chimera | Creature | Chimera | Flying
{2}{U}{R}: Scry 1, then reveal the top card of your library. Stormchaser Chimera gets +X/+0 until end of turn, where X is that card's mana value. (To scry 1, look at the top card of your library, then you may put that card on the bottom of your library.) | Greg Staples
Fleetfeather Cockatrice | Creature | Cockatrice | Flash (You may cast this spell any time you could cast an instant.)
Flying, deathtouch
{5}{G}{U}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.) | Matt Stewart
Kruphix, God of Horizons | Legendary Enchantment Creature | God | Indestructible
As long as your devotion to green and blue is less than seven, Kruphix isn't a creature.
You have no maximum hand size.
If you would lose unspent mana, that mana becomes colorless instead. | Daarken