Power Fist

Equipped creature has trample and "Whenever this creature deals combat damage to a player, put that many +1/+1 counters on it."
Equip {2}

Blasphemous Act

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

Ravages of War

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Nuka-Cola Vending Machine

{1}, {T}: Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Whenever you sacrifice a Food, create a tapped Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Pip-Boy 3000

Whenever equipped creature attacks, choose one —
• Sort Inventory — Draw a card, then discard a card.
• Pick a Perk — Put a +1/+1 counter on that creature.
• Check Map — Untap up to two target lands.
Equip {2}

Arcane Signet

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

Walking Ballista

Walking Ballista enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.