Mountain

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Crackle with Power

Crackle with Power deals five times X damage to each of up to X targets.

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Jaya's Immolating Inferno

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Jaya's Immolating Inferno deals X damage to each of up to three targets.

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice Emergence Zone: You may cast spells this turn as though they had flash.

Ashling, Flame Dancer

You don't lose unspent red mana as steps and phases end.
Magecraft — Whenever you cast or copy an instant or sorcery spell, discard a card, then draw a card. If this is the second time this ability has resolved this turn, Ashling, Flame Dancer deals 2 damage to each opponent and each creature they control. If it's the third time, add {R}{R}{R}{R}.