Boros Signet

Monastery Mentor

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a noncreature spell, create a 1/1 white Monk creature token with prowess.

Boros Locket

{T}: Add {R} or {W}.
{R/W}{R/W}{R/W}{R/W}, {T}, Sacrifice Boros Locket: Draw two cards.

Tear

Destroy target enchantment.
Fuse (You may cast one or both halves of this card from your hand.)

Wear

Destroy target artifact.
Fuse (You may cast one or both halves of this card from your hand.)

Wear // Tear

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Feather, the Redeemed

Flying
Whenever you cast an instant or sorcery spell that targets a creature you control, exile that card instead of putting it into your graveyard as it resolves. If you do, return it to your hand at the beginning of the next end step.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Mirrorwing Dragon

Flying
Whenever a player casts an instant or sorcery spell that targets only Mirrorwing Dragon, that player copies that spell for each other creature they control that the spell could target. Each copy targets a different one of those creatures.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Paradox Engine

Whenever you cast a spell, untap all nonland permanents you control.

Sunforger

Equipped creature gets +4/+0.
{R}{W}, Unattach Sunforger: Search your library for a red or white instant card with mana value 4 or less and cast that card without paying its mana cost. Then shuffle.
Equip {3}

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Recruiter of the Guard

When Recruiter of the Guard enters, you may search your library for a creature card with toughness 2 or less, reveal it, put it into your hand, then shuffle.

Arid Mesa

{T}, Pay 1 life, Sacrifice Arid Mesa: Search your library for a Mountain or Plains card, put it onto the battlefield, then shuffle.

Eerie Interlude

Exile any number of target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Cloudshift

Exile target creature you control, then return that card to the battlefield under your control.

Unwinding Clock

Untap all artifacts you control during each other player's untap step.

Akroan Crusader

Heroic — Whenever you cast a spell that targets Akroan Crusader, create a 1/1 red Soldier creature token with haste. (It can attack and {T} as soon as it comes under your control.)

Plains

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters, you may pay 2 life. If you don't, it enters tapped.

Clifftop Retreat

Clifftop Retreat enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Mountain

Plateau

Defiant Strike

Target creature gets +1/+0 until end of turn.
Draw a card.

Vanguard of Brimaz

Vigilance
Heroic — Whenever you cast a spell that targets Vanguard of Brimaz, create a 1/1 white Cat Soldier creature token with vigilance.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Guided Strike

Target creature gets +1/+0 and gains first strike until end of turn.
Draw a card.

Zada, Hedron Grinder

Whenever you cast an instant or sorcery spell that targets only Zada, Hedron Grinder, copy that spell for each other creature you control that the spell could target. Each copy targets a different one of those creatures.

Imperial Recruiter

When Imperial Recruiter enters, search your library for a creature card with power 2 or less, reveal it, put it into your hand, then shuffle.

Victory Chimes

Untap Victory Chimes during each other player's untap step.
{T}: A player of your choice adds {C}.

Sol Ring

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Land Tax

At the beginning of your upkeep, if an opponent controls more lands than you, you may search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.