Eidolon of Inspiration

At the beginning of combat on your turn, target creature you control gets +2/+0 until end of turn.

Plains

Elspeth's Devotee

When Elspeth's Devotee enters, you may search your library and/or graveyard for a card named Elspeth, Undaunted Hero, reveal it, and put it into your hand. If you search your library this way, shuffle.

Hero of the Winds

Flying
Whenever you cast a spell that targets Hero of the Winds, creatures you control get +1/+0 until end of turn.

Indomitable Will

Flash
Enchant creature
Enchanted creature gets +1/+2.

Archon of Falling Stars

Flying
When Archon of Falling Stars dies, you may return target enchantment card from your graveyard to the battlefield.

Karametra's Blessing

Target creature gets +2/+2 until end of turn. If it's an enchanted creature or enchantment creature, it also gains hexproof and indestructible until end of turn. (It can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Sunlit Hoplite

During your turn, Sunlit Hoplite has first strike.
Sunlit Hoplite gets +1/+0 as long as you control an Elspeth planeswalker.

Taranika, Akroan Veteran

Vigilance
Whenever Taranika, Akroan Veteran attacks, untap another target creature you control. Until end of turn, that creature has base power and toughness 4/4 and gains indestructible.

Dreadful Apathy

Enchant creature
Enchanted creature can't attack or block.
{2}{W}: Exile enchanted creature.

Elspeth, Undaunted Hero

+2: Put a +1/+1 counter on each of up to two target creatures.
−2: Search your library and/or graveyard for a card named Sunlit Hoplite and put it onto the battlefield. If you search your library this way, shuffle.
−8: Until end of turn, creatures you control gain flying and get +X/+X, where X is your devotion to white.

Leonin of the Lost Pride

When Leonin of the Lost Pride dies, exile target card from an opponent's graveyard.

Phalanx Tactics

Target creature you control gets +2/+1 until end of turn. Each other creature you control gets +1/+1 until end of turn.

Daybreak Chimera

This spell costs {X} less to cast, where X is your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)
Flying

Daxos, Blessed by the Sun

Daxos's toughness is equal to your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)
Whenever another creature you control enters or dies, you gain 1 life.