Skred

Skred deals damage to target creature equal to the number of snow permanents you control.

Snow-Covered Island

Highland Lake

Highland Lake enters tapped.
{T}: Add {U} or {R}.

Volatile Fjord

({T}: Add {U} or {R}.)
Volatile Fjord enters tapped.

Rite of Flame

Add {R}{R}, then add {R} for each card named Rite of Flame in each graveyard.

Disintegrate

Disintegrate deals X damage to any target. If it's a creature, it can't be regenerated this turn, and if it would die this turn, exile it instead.

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

Snow-Covered Mountain

Erebor Flamesmith

Whenever you cast an instant or sorcery spell, Erebor Flamesmith deals 1 damage to each opponent.

Experimental Synthesizer

When Experimental Synthesizer enters or leaves the battlefield, exile the top card of your library. Until end of turn, you may play that card.
{2}{R}, Sacrifice Experimental Synthesizer: Create a 2/2 white Samurai creature token with vigilance. Activate only as a sorcery.

Teach by Example

When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.