Have

Unclaimed Territory

As Unclaimed Territory enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Relief Captain

When Relief Captain enters, support 3. (Put a +1/+1 counter on each of up to three other target creatures.)

Expedition Envoy

Forest

Hada Freeblade

Whenever Hada Freeblade or another Ally you control enters, you may put a +1/+1 counter on Hada Freeblade.

Turntimber Ranger

Whenever Turntimber Ranger or another Ally you control enters, you may create a 2/2 green Wolf creature token. If you do, put a +1/+1 counter on Turntimber Ranger.

Tajuru Warcaller

Rally — Whenever Tajuru Warcaller or another Ally you control enters, creatures you control get +2/+2 until end of turn.

Plains

Beastcaller Savant

Haste
{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

Getting

Ally Encampment

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast an Ally spell.
{1}, {T}, Sacrifice Ally Encampment: Return target Ally you control to its owner's hand.

Oran-Rief Survivalist

Whenever Oran-Rief Survivalist or another Ally you control enters, you may put a +1/+1 counter on Oran-Rief Survivalist.