Careful Study

Elvish Spirit Guide

Exile Elvish Spirit Guide from your hand: Add {G}.

Phantom Nishoba

Trample
Phantom Nishoba enters the battlefield with seven +1/+1 counters on it.
Whenever Phantom Nishoba deals damage, you gain that much life.
If damage would be dealt to Phantom Nishoba, prevent that damage. Remove a +1/+1 counter from Phantom Nishoba.

Island

City of Brass

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

Ashen Firebeast

{1}{R}: Ashen Firebeast deals 1 damage to each creature without flying.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Sneak Attack

{R}: You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Gemstone Mine

Gemstone Mine enters the battlefield with three mining counters on it.
{T}, Remove a mining counter from Gemstone Mine: Add one mana of any color. If there are no mining counters on Gemstone Mine, sacrifice it.

City of Traitors

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

Form of the Dragon

At the beginning of your upkeep, Form of the Dragon deals 5 damage to any target.
At the beginning of each end step, your life total becomes 5.
Creatures without flying can't attack you.

Crosis's Catacombs

When Crosis's Catacombs enters the battlefield, sacrifice it unless you return a non-Lair land you control to its owner's hand.
{T}: Add {U}, {B}, or {R}.

Akroma, Angel of Wrath

Flying, first strike, vigilance, trample, haste, protection from black and from red

Show and Tell

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

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Decree of Silence

Whenever an opponent casts a spell, counter that spell and put a depletion counter on Decree of Silence. If there are three or more depletion counters on Decree of Silence, sacrifice it.
Cycling {4}{U}{U} ({4}{U}{U}, Discard this card: Draw a card.)
When you cycle Decree of Silence, you may counter target spell.

Portent

Look at the top three cards of target player's library, then put them back in any order. You may have that player shuffle.
Draw a card at the beginning of the next turn's upkeep.