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.

Grow from the Ashes

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Search your library for a basic land card, put it onto the battlefield, then shuffle. If this spell was kicked, instead search your library for two basic land cards, put them onto the battlefield, then shuffle.

Halana and Alena, Partners

First strike (This creature deals combat damage before creatures without first strike.)
Reach (This creature can block creatures with flying.)
At the beginning of combat on your turn, put X +1/+1 counters on another target creature you control, where X is Halana and Alena's power. That creature gains haste until end of turn.

Mold Shambler

Kicker {1}{G} (You may pay an additional {1}{G} as you cast this spell.)
When this creature enters, if it was kicked, destroy target noncreature permanent.

Elfhame Druid

{T}: Add {G}.
{T}: Add {G}{G}. Spend this mana only to cast kicked spells.

Hallar, the Firefletcher

Trample
Whenever you cast a spell, if that spell was kicked, put a +1/+1 counter on Hallar, then Hallar deals damage equal to the number of +1/+1 counters on it to each opponent.

Murasa Sproutling

Kicker {1}{G} (You may pay an additional {1}{G} as you cast this spell.)
When this creature enters, if it was kicked, return target card with a kicker ability from your graveyard to your hand.