Maelstrom Archangel

Flying
Whenever this creature deals combat damage to a player, you may cast a spell from your hand without paying its mana cost.

Roil Elemental

Flying
Landfall — Whenever a land you control enters, you may gain control of target creature for as long as you control this creature.

Doubling Cube

{3}, {T}: Double the amount of each type of unspent mana you have.

Crackle with Power

Crackle with Power deals five times X damage to each of up to X targets.

Genesis Wave

Reveal the top X cards of your library. You may put any number of permanent cards with mana value X or less from among them onto the battlefield. Then put all cards revealed this way that weren't put onto the battlefield into your graveyard.

Rocco, Cabaretti Caterer

When Rocco enters, if you cast it, you may search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

Tatyova, Benthic Druid

Landfall — Whenever a land you control enters, you gain 1 life and draw a card.

Distorting Wake

Return X target nonland permanents to their owners' hands.

Lavalanche

Lavalanche deals X damage to target player or planeswalker and each creature that player or that planeswalker's controller controls.

Debt to the Deathless

Each opponent loses two times X life. You gain life equal to the life lost this way.

Nyxbloom Ancient

Trample
If you tap a permanent for mana, it produces three times as much of that mana instead.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Perennial Behemoth

You may play lands from your graveyard.
Unearth {G}{G} ({G}{G}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Mana Reflection

If you tap a permanent for mana, it produces twice as much of that mana instead.

Beseech the Queen

({2/B} can be paid with any two mana or with {B}. This card's mana value is 6.)
Search your library for a card with mana value less than or equal to the number of lands you control, reveal it, put it into your hand, then shuffle.