Raid Bombardment

Whenever a creature you control with power 2 or less attacks, this enchantment deals 1 damage to the player or planeswalker that creature is attacking.

Vexing Devil

When this creature enters, any opponent may have it deal 4 damage to them. If a player does, sacrifice this creature.

Zurzoth, Chaos Rider

Whenever an opponent draws their first card each turn, if it's not their turn, you create a 1/1 red Devil creature token with "When this token dies, it deals 1 damage to any target."
Whenever one or more Devils you control attack one or more players, you and those players each draw a card, then discard a card at random.

Sin Prodder

Menace
At the beginning of your upkeep, reveal the top card of your library. Any opponent may have you put that card into your graveyard. If a player does, this creature deals damage to that player equal to that card's mana value. Otherwise, put that card into your hand.

Geth's Grimoire

Whenever an opponent discards a card, you may draw a card.

Ruby Medallion

Red spells you cast cost {1} less to cast.

Sol Ring

Winter Sky

Flip a coin. If you win the flip, Winter Sky deals 1 damage to each creature and each player. If you lose the flip, each player draws a card.

Sower of Chaos

{2}{R}: Target creature can't block this turn.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Burning Inquiry

Each player draws three cards, then discards three cards at random.

Seething Song

Goblin Bombardment

Sacrifice a creature: This enchantment deals 1 damage to any target.

Cavalcade of Calamity

Whenever a creature you control with power 1 or less attacks, this enchantment deals 1 damage to the player or planeswalker that creature is attacking.

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Mountain

Mikokoro, Center of the Sea

{T}: Add {C}.
{2}, {T}: Each player draws a card.

Vengeful Devil

Haste
Morbid — {T}: This creature deals 1 damage to any target. Activate only if a creature died this turn.

Arcane Signet

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

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.