Enchant creature you control Enchanted creature gets +1/+1. When enchanted creature dies, return it to the battlefield under your control, then arm it. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)
Target creature you control explores. Then it fights up to one target creature you don't control. If that creature has flying, the creature you control deals damage equal to its power to it instead. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then you may put that card in your graveyard.)
Ungoverned Sneak can't be blocked by creatures with greater power. Attain {3}{U}({3}{U}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)
Return target creature card from your graveyard to your hand. Inscribe {3}{B}({3}{B}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)
In Althestra, Phyrexia used the dark ancient force that lingered to rise the dead who still had all the expertise they did when they were alive, only they now used it against their own brethren.
Starting with you, each player may sacrifice a creature. Each player that doesn't loses life equal to the total power of creatures sacrificed this way.
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.) United Patrol can block an additional creature each combat.
University Archive enters tapped. When University Archive enters, look at the top card of your library. You may put it into your graveyard. {T}: Add {U} or {R}.
When Unmarked Vials enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”) {1}, {T}: Add one mana of any color.
Kicker {1}{U}(You may pay an additional {1}{U} as you cast this spell.) Tap up to three target creatures. If this spell was kicked, those creatures don't untap during their controller's next untap step.
Target creature you control gains erratic until end of turn. You may have it fight another target creature. (When this creature dies, reveal the top four cards of your library. Put a creature card that costs less than this revealed this way onto the battlefield and the rest on the bottom of your library in any order.)
Add X mana in any combination of colors, where X is the amount of mana spent to cast Unravel Shattered Worlds. Coalesce {7}(You may cast this from your graveyard for {7}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Draw a card. If this spell was foretold, instead surveil 2, then draw two cards. Foretell {2}{U}(During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Glitch—Sacrifice a creature. (Remove one [restriction] for each time you pay the glitch cost.) When Unshackled Revolutionary enters, you may destroy target creature an opponent controls [with mana value 3 or less]. [You lose 3 life.]