Witherbloom, the Balancer

Affinity for creatures (This spell costs {1} less to cast for each creature you control.)
Flying, deathtouch
Instant and sorcery spells you cast have affinity for creatures.

Chain of Smog

Target player discards two cards. That player may copy this spell and may choose a new target for that copy.

Dark Ritual

Sprout Swarm

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Create a 1/1 green Saproling creature token.

Chatterstorm

Create a 1/1 green Squirrel creature token.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Witherbloom Apprentice

Magecraft — Whenever you cast or copy an instant or sorcery spell, each opponent loses 1 life and you gain 1 life.