Bartz and Boko

Affinity for Birds (This spell costs {1} less to cast for each Bird you control.)
When Bartz and Boko enters, each other Bird you control deals damage equal to its power to target creature an opponent controls.

Sazh Katzroy

When Sazh Katzroy enters, you may search your library for a Bird or basic land card, reveal it, put it into your hand, then shuffle.
Whenever Sazh Katzroy attacks, put a +1/+1 counter on target creature, then double the number of +1/+1 counters on that creature.

Wooded Foothills

{T}, Pay 1 life, Sacrifice this land: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Birds of Paradise

Sazh's Chocobo

Landfall — Whenever a land you control enters, put a +1/+1 counter on this creature.

Chocobo Kick

Kicker—Return a land you control to its owner's hand. (You may return a land you control to its owner's hand in addition to any other costs as you cast this spell.)
Target creature you control deals damage equal to its power to target creature an opponent controls. If this spell was kicked, the creature you control deals twice that much damage instead.

Chocobo Camp

This land enters tapped unless you control a legendary creature.
{T}: Add {G}. When you next cast a Bird creature spell this turn, it enters with an additional +1/+1 counter on it.
{2}{G}{G}, {T}: Create a 2/2 green Bird creature token with "Whenever a land you control enters, this token gets +1/+0 until end of turn."

Bird

Whenever a land you control enters, this token gets +1/+0 until end of turn.

Clash of the Eikons

Choose one or more —
• Target creature you control fights target creature an opponent controls.
• Remove a lore counter from target Saga you control. (Removing lore counters doesn't cause chapter abilities to trigger.)
• Put a lore counter on target Saga you control.

Traveling Chocobo

You may look at the top card of your library any time.
You may play lands and cast Bird spells from the top of your library.
If a land or Bird you control entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Ride the Shoopuf

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature you control.
{5}{G}{G}: This enchantment becomes a 7/7 Beast creature in addition to its other types.

Black Chocobo

When this permanent transforms into Black Chocobo, search your library for a land card, put it onto the battlefield tapped, then shuffle.
Landfall — Whenever a land you control enters, Birds you control get +1/+0 until end of turn.

Sidequest: Raise a Chocobo

When this enchantment enters, create a 2/2 green Bird creature token with "Whenever a land you control enters, this token gets +1/+0 until end of turn."
At the beginning of your first main phase, if you control four or more Birds, transform this enchantment.

Sidequest: Raise a Chocobo // Black Chocobo

Bristly Bill, Spine Sower

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature.
{3}{G}{G}: Double the number of +1/+1 counters on each creature you control.

Windswept Heath

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.