Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Mountain

Geomancer's Gambit

Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.
Draw a card.

Spell Crumple

Counter target spell. If that spell is countered this way, put it on the bottom of its owner's library instead of into that player's graveyard. Put Spell Crumple on the bottom of its owner's library.

Island

Cleansing Wildfire

Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield tapped, then shuffle.
Draw a card.

River Song

Meet in Reverse — You draw cards from the bottom of your library rather than the top.
Spoilers — Whenever an opponent scries, surveils, or searches their library, put a +1/+1 counter on River Song. Then River Song deals damage to that player equal to its power.

Noble Benefactor

When Noble Benefactor dies, each player may search their library for a card and put that card into their hand. Then each player who searched their library this way shuffles.

Krenko's Buzzcrusher

Flying, trample
When Krenko's Buzzcrusher enters, for each player, destroy up to one nonbasic land that player controls. For each land destroyed this way, its controller may search their library for a basic land card, put it onto the battlefield tapped, then shuffle.

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Experimental Augury

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)