Crosis's Catacombs

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

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.

Island

Duress

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

Gemstone Mine

Gemstone Mine enters 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.

Ashen Firebeast

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

City of Traitors

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

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.

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.

Shivan Reef

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

Phantom Nishoba

Trample
Phantom Nishoba enters 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.

City of Brass

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

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.

Akroma, Angel of Wrath

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

Elvish Spirit Guide

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

Careful Study

Show and Tell

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