Agatha's Soul Cauldron

You may spend mana as though it were mana of any color to activate abilities of creatures you control.
Creatures you control with +1/+1 counters on them have all activated abilities of all creature cards exiled with Agatha's Soul Cauldron.
{T}: Exile target card from a graveyard. When a creature card is exiled this way, put a +1/+1 counter on target creature you control.

Foggy Swamp Visions

As an additional cost to cast this spell, waterbend {X}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
Exile X target creature cards from graveyards. For each creature card exiled this way, create a token that's a copy of it. At the beginning of your next end step, sacrifice those tokens.

Sandsteppe Citadel

This land enters tapped.
{T}: Add {W}, {B}, or {G}.

Hushwood Verge

{T}: Add {G}.
{T}: Add {W}. Activate only if you control a Forest or a Plains.

Avatar's Wrath

Choose up to one target creature, then airbend all other creatures. (Exile them. While each one is exiled, its owner may cast it for {2} rather than its mana cost.)
Until your next turn, your opponents can't cast spells from anywhere other than their hand.
Exile Avatar's Wrath.

Forest

Plains

Godless Shrine

({T}: Add {W} or {B}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Swamp

Great Arashin City

This land enters tapped unless you control a Forest or a Plains.
{T}: Add {B}.
{1}{B}, {T}, Exile a creature card from your graveyard: Create a 1/1 white Spirit creature token.

Wastewood Verge

{T}: Add {G}.
{T}: Add {B}. Activate only if you control a Swamp or a Forest.

Cosmogoyf

This creature's power is equal to the number of cards you own in exile and its toughness is equal to that number plus 1.