Don't Try This at Home

If a hot source you control would deal damage to a permanent or player, it deals that much damage plus 1 instead. (Something is hot if it has hot things in its art, like fire or explosions.)
{1}{R}, Sacrifice Don't Try This at Home: It deals damage equal to twice the number of hot cards in your graveyard to target creature or planeswalker.

Swamp

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. Sulfurous Springs deals 1 damage to you.

Rakdos Trumpeter

Menace (This creature can't be blocked except by two or more creatures.)
{3}{R}: Rakdos Trumpeter gets +2/+0 until end of turn.

Cut Down

Destroy target creature with total power and toughness 5 or less.

Fireblade Artist

Haste
At the beginning of your upkeep, you may sacrifice a creature. When you do, Fireblade Artist deals 2 damage to target opponent or planeswalker.

Torch Fiend

{R}, Sacrifice Torch Fiend: Destroy target artifact.

Arc Runner

Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice Arc Runner.

Footlight Fiend

When Footlight Fiend dies, it deals 1 damage to any target.

Murder

Mountain

Baron Von Count

Baron Von Count enters with a doom counter on "5."
Whenever you cast a spell with the indicated numeral in its mana cost, text box, power, or toughness, move the doom counter one numeral to the left.
When the doom counter moves from "1," destroy target player and put that doom counter on "5."

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 creature 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.