Search your library for a card with flashback and exile it, then shuffle. You may cast that card this turn. At the beginning of your next end step, if that card is in exile, put it into your graveyard.
Flashback {U}{R}

Flash
Flying

Lifelink
Landfall — Whenever a land you control enters, create a Berry token. You may attach it to Rooting Raccoon.

Trample
Ruin, the First Shard enters with a +1/+1 counter on it for each mana spent to cast it.

Choose any number of permanent cards in your graveyard put there from the battlefield this turn. Return one of them to the battlefield and the rest to your hand.
Cycling {W/B}

Sacrifice any number of permanents. Ruinous Portents deals X damage to each creature your opponents control and you draw X cards, where X is the number of permanents sacrificed this way.

Choose one or both —
• Target creature gets +1/+1 until end of turn.
• Return target creature to its owner's hand.

{2}, Sacrifice this creature: Create a 2/2 white Samurai creature token with exalted. Activate only as a sorcery.

[+1]: Up to one target nonland permanent gets -1/-1 and loses all abilities until your next turn.
[0]: Target creature you control gets +2/+2 and gains lifelink until your next turn.
[–1]: Each player discards a card. Then you may pay 2 life. If you do, draw a card.
[–3]: You and target opponent's life totals each become equal to half your combined life totals, rounded down.

As an additional cost to cast this spell, exile X cards from your graveyard.
You draw X cards and gain X life, then each opponent loses X life.

Whenever Scattering Swine deals combat damage to a player, you may return a permanent you control to its owner's hand. If you do, defending player loses 3 life unless they discard a card that shares a type with the returned permanent.

Sacrifice another creature: This creature gets +2/+1 until end of turn. Activate only once each turn.

Haste
This creature enters with a +1/+1 counter on it.
When this creature dies, you may put its counters on target creature you control.

Whenever one or more creatures you control deal combat damage to a player, you may draw that many cards. If you do, discard a card.
Exile two creature cards from your graveyard: Scrapyard Mecha becomes an artifact creature until end of turn. Activate only as a sorcery.
Crew 2

Whenever a Subroutine you control enters, you may pay {2}. If you do, it runs.
Whenever a Subroutine you control runs, this creature gets +1/+1 until end of turn.

When Seafloor Scavenger enters or deals combat damage to a player, you may return target exiled card with surface you own to your hand.

At the beginning of each end step, create a 2/2 white and blue Seal Orb creature token if you activated two or more nonmana abilities this turn.
{W}{U}: Scry 1. You gain 1 life.

Target player reveals their hand. You may choose a nonland card from it. If you do, that player discards that card. Otherwise, draw a card.

Whenever this enchantment or another nonland, nontoken permanent you control enters, if it wasn't cast, draw a card. You may put a land card from your hand onto the battlefield tapped.
Creatures you control with power or toughness 1 or less can't be blocked.

Flash
When Security Initiative enters, you may tap or untap target nonland permanent. Then draw a card.
An opponent controls three or more tapped nonland permanents.

Vigilance
{1}, {T}: Tap target creature.

You may remove +1/+1 counters from creatures you control as though they were loyalty counters on Severin, Sparkmind to pay its loyalty costs.
[0]: Create a 0/0 colorless Robot artifact creature token with two +1/+1 counters on it.
[–2]: You may tap or untap each of up to three target permanents.
[–7]: If it isn't an extra turn, take an extra turn after this one.

Solidarity
You may look at the top card of your library any time.
You may cast creature spells that have a creature type no creature you control does from the top of your library.

Vigilance
Whenever you cast a spell from anywhere other than your hand, put a +1/+1 counter on Shepherd of Steel.
When Shepherd of Steel dies, put its counters on target creature you control.

At the beginning of your end step, create a 1/1 blue Ninja creature token with “This creature can't be blocked by creatures with greater power.”
Whenever you activate a ninjutsu ability for the first time each turn, untap up to two target lands you control.