Forbidden Orchard

{T}: Add one mana of any color.
Whenever you tap Forbidden Orchard for mana, target opponent creates a 1/1 colorless Spirit creature token.

City of Brass

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Pact of Negation

Counter target spell.
At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Brainstorm

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

Noble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {G}, {W}, or {U}.

Pact of the Titan

Create a 4/4 red Giant creature token.
At the beginning of your next upkeep, pay {4}{R}. If you don't, you lose the game.

Manamorphose

Add two mana in any combination of colors.
Draw a card.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Hive Mind

Whenever a player casts an instant or sorcery spell, each other player copies that spell. Each of those players may choose new targets for their copy.

City of Traitors

When you play another land, sacrifice City of Traitors.
{T}: Add {C}{C}.

Show and Tell

Each player may put an artifact, creature, enchantment, or land card from their hand onto the battlefield.

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Enlightened Tutor

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.