Gaea's Balance

As an additional cost to cast this spell, sacrifice five lands.
Search your library for a land card of each basic land type, put those cards onto the battlefield, then shuffle.

Idyllic Beachfront

({T}: Add {W} or {U}.)
Idyllic Beachfront enters tapped.

Etched Monstrosity

Etched Monstrosity enters with five -1/-1 counters on it.
{W}{U}{B}{R}{G}, Remove five -1/-1 counters from Etched Monstrosity: Target player draws three cards.

Plains

Courier's Briefcase

When Courier's Briefcase enters, create a 1/1 green and white Citizen creature token.
{T}, Sacrifice Courier's Briefcase: Add one mana of any color.
{W}{U}{B}{R}{G}, {T}, Sacrifice Courier's Briefcase: Draw three cards.

Molten Tributary

({T}: Add {U} or {R}.)
Molten Tributary enters tapped.

Wooded Ridgeline

({T}: Add {R} or {G}.)
Wooded Ridgeline enters tapped.

Tangled Islet

({T}: Add {G} or {U}.)
Tangled Islet enters tapped.

Haunted Mire

({T}: Add {B} or {G}.)
Haunted Mire enters tapped.

Swamp

Dragonsoul Knight

First strike
{W}{U}{B}{R}{G}: Until end of turn, Dragonsoul Knight becomes a Dragon, gets +5/+3, and gains flying and trample.

Island

Contaminated Aquifer

({T}: Add {U} or {B}.)
Contaminated Aquifer enters tapped.

Wandering Stream

Domain — You gain 2 life for each basic land type among lands you control.

Geothermal Bog

({T}: Add {B} or {R}.)
Geothermal Bog enters tapped.

Path to the World Tree

When Path to the World Tree enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{2}{W}{U}{B}{R}{G}, Sacrifice Path to the World Tree: You gain 2 life and draw two cards. Target opponent loses 2 life. Path to the World Tree deals 2 damage to up to one target creature. You create a 2/2 green Bear creature token.

Kaleidoscorch

Converge — Kaleidoscorch deals X damage to any target, where X is the number of colors of mana spent to cast this spell.
Flashback {4}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sunlit Marsh

({T}: Add {W} or {B}.)
Sunlit Marsh enters tapped.

Fusion Elemental

Radiant Grove

({T}: Add {G} or {W}.)
Radiant Grove enters tapped.

Forest

Drag to the Bottom

Domain — Each creature gets -X/-X until end of turn, where X is 1 plus the number of basic land types among lands you control.

Mountain

Last Stand

Target opponent loses 2 life for each Swamp you control. Last Stand deals damage to target creature equal to the number of Mountains you control. Create a 1/1 green Saproling creature token for each Forest you control. You gain 2 life for each Plains you control. Draw a card for each Island you control, then discard that many cards.

Channel the Suns

Paragon of the Amesha

First strike
{W}{U}{B}{R}{G}: Until end of turn, Paragon of the Amesha becomes an Angel, gets +3/+3, and gains flying and lifelink.

Kaleidostone

When Kaleidostone enters, draw a card.
{5}, {T}, Sacrifice Kaleidostone: Add {W}{U}{B}{R}{G}.