Mountain

Memory Lapse

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

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Sphinx's Revelation

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Circle of Protection: Blue

{1}: The next time a blue source of your choice would deal damage to you this turn, prevent that damage.

Browbeat

Any player may have Browbeat deal 5 damage to them. If no one does, target player draws three cards.

Brainstorm

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

Thunderheads

Replicate {2}{U} (When you cast this spell, copy it for each time you paid its replicate cost.)
Create a 3/3 blue Weird creature token with defender and flying. Exile it at the beginning of the next end step.

Brainstone

{2}, {T}, Sacrifice Brainstone: Draw three cards, then put two cards from your hand on top of your library in any order.

Enter the Infinite

Draw cards equal to the number of cards in your library, then put a card from your hand on top of your library. You have no maximum hand size until your next turn.