Draw a card. Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)
Faith in a conjecture meets the challenge of proving it.
Whenever you cycle a card, scry 1. (Do this before you draw.) {W}{U}{B}{R}{G}, Sacrifice Maelstromancy: Return up to three target cards with cycling abilities from your graveyard to your hand.
Choose two — • Target player creates a 1/1 blue Wizard creature token with prowess. • Target player draws two cards, then discards two cards. • Tap up to two target creatures. • Target creature or player gains hexproof until end of turn.
Flying At the beginning of your upkeep, if it isn't an extra turn, put a sage counter on Magistrate of Eras. Remove five sage counters from Magistrate of Eras: Take an extra turn after this one.
Tap up to two target creatures an opponent controls. Those creatures don't untap during their controller's next untap step. Create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
Counter target spell. If a permanent spell is countered this way, you may aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)
The Cosmos gives; the Cosmos takes. What is left is void.
[+1]: Scry 2. Whenever one or more creatures you control deal combat damage to a player this turn, draw a card. [–2]: Create a token that's a copy of target creature you control, except the token is 4/4 and has vigilance. [–7]: You get an emblem with “At the beginning of your draw step, draw two additional cards” and “Creatures you control get +1/+1 for each card you've drawn this turn.”
Choose one — • Counter target spell unless its controller pays {2}. • Change the target of target spell with a single target unless that spell's controller pays {2}.
Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.) Whenever Manipulator of Waves attacks, mill three cards. Then create a 0/0 blue Elemental Serpent creature token with “This creature gets +1/+1 for each five cards in your graveyard.”
Deception {2}{U}({2}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) Whenever Marilye deals combat damage to a player, you may search your library for an artifact card with mana value less than or equal to that amount of damage, put it onto the battlefield, then shuffle.
Deception {2}{U}{U}({2}{U}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) As long as it's your turn, Marilye is a 3/2 Elf Rogue creature with hexproof and indestructible. [+1]: Tap target permanent. It doesn't untap during its controller's next untap step. [–2]: Exile the top five cards of target opponent's library. You may cast any number of cards exiled this way with total mana value less than or equal to the amount of damage dealt to them this turn without paying their mana costs.
You may spend mana as if it was mana of any color to cast cards exiled with Marilye. [+1]: Exile the top card of each opponent's library. Until end of turn, you may cast spells from among those exiled cards. [–3]: Exile target creature. You may cast that card. If you don't, return it to its owner's hand. [–7]: Gain control of up to five target nonland permanents.
Marin Polgek, Academy Heiress has hexproof as long as you control three or more enchantments. {1}{W/U}{W/U}: Create a token that's a copy of target enchantment you control.