Sunderflock

This spell costs {X} less to cast, where X is the greatest mana value among Elementals you control.
Flying
When this creature enters, if you cast it, return all non-Elemental creatures to their owners' hands.

Changeling Wayfinder

Changeling (This card is every creature type.)
When this creature enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Stratosoarer

Flying
When this creature enters, target creature gains flying until end of turn.
Basic landcycling {1}{U} ({1}{U}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Kirol, Attentive First-Year

Tap two untapped creatures you control: Copy target triggered ability you control. You may choose new targets for the copy. Activate only once each turn.

Kindle the Inner Flame

Create a token that's a copy of target creature you control, except it has haste and "At the beginning of the end step, sacrifice this token."
Flashback—{1}{R}, Behold three Elementals. (You may cast this card from your graveyard for its flashback cost. Then exile it. To behold an Elemental, choose an Elemental you control or reveal an Elemental card from your hand.)

Tweeze

Tweeze deals 3 damage to any target. You may discard a card. If you do, draw a card.

Eclipsed Realms

As this land enters, choose Elemental, Elf, Faerie, Giant, Goblin, Kithkin, Merfolk, or Treefolk.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a spell of the chosen type or activate an ability of a source of the chosen type.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.