Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Sacred Foundry

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

Anointed Procession

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Jor Kadeen, the Prevailer

First strike
Metalcraft — Creatures you control get +3/+0 as long as you control three or more artifacts.

Tempered Steel

Artifact creatures you control get +2/+2.

Command Tower

One-Clown Band

{2}{R}: Target Robot gets +2/+0 until end of turn.

Surprise Party

When Surprise Party enters the battlefield, yell "Surprise!" and put onto the battlefield any number of printed Clown Robot tokens that aren't touching each other, that you hid on the battlefield before you cast Surprise Party, and that weren't spotted by an opponent before you cast Surprise Party.
Robots you control get +1/+0 and have vigilance.

Information Booth

Clown Car

When Clown Car enters the battlefield, roll X six-sided dice. For each odd result, create a 1/1 white Clown Robot artifact creature token. For each even result, put a +1/+1 counter on Clown Car.
Crew 2

Clowning Around

Create two 1/1 white Clown Robot artifact creature tokens, then roll a six-sided die. If the result is equal to or less than the number of Robots you control, create a 1/1 white Clown Robot artifact creature token.

Pietra, Crafter of Clowns

Haste
Robots you control get +1/+1.
{R}{W}, {T}, Tell a joke you haven't told this game to someone outside the game: Create a 1/1 white Clown Robot artifact creature token. If that person laughed, the token gains haste until end of turn.

Organic Extinction

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Destroy all nonartifact creatures.

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

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.")

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Complaints Clerk

When Complaints Clerk enters the battlefield, open an Attraction. (Put the top card of your Attraction deck onto the battlefield.)
Whenever you roll a 1, create a 1/1 white Clown Robot artifact creature token.

Boros Signet

Plateau

Spectator Seating

Spectator Seating enters the battlefield tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Celebr-8000

At the beginning of combat on your turn, roll two six-sided dice. For each result of 1, Celebr-8000 gets +1/+1 until end of turn. For each other result, it gains the indicated ability until end of turn. If you rolled doubles, it also gains double strike until end of turn.
• 2 — menace
• 3 — vigilance
• 4 — lifelink
• 5 — flying
• 6 — indestructible

Dispatch

Tap target creature.
Metalcraft — If you control three or more artifacts, exile that creature.

Swords to Plowshares

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

Clown Extruder

Visit — Create a 1/1 white Clown Robot artifact creature token.

Mentor of the Meek

Whenever another creature with power 2 or less enters the battlefield under your control, you may pay {1}. If you do, draw a card.

Circuits Act

Roll three six-sided dice. For each different result, create a 1/1 white Clown Robot artifact creature token.

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Hour of Reckoning

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy all nontoken creatures.

Talisman of Conviction

{T}: Add {C}.
{T}: Add {R} or {W}. Talisman of Conviction deals 1 damage to you.

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Assembled Ensemble

Vigilance
Assembled Ensemble's power is equal to the number of Robots you control.
Whenever you cast a spell with an artifact creature in its art, create a 1/1 white Clown Robot artifact creature token.

Pie-roclasm

Pie-roclasm deals π damage to each non-Clown creature. (How to calculate π isn't important. It's a smidgen more than 3.)

Omniclown Colossus

Affinity for Clowns (This spell costs {1} less to cast for each Clown you control.)
Trample