Devoted Paladin

Beacon of Hope — When Devoted Paladin enters, creatures you control get +1/+1 and gain vigilance until end of turn.

Dawnbringer Cleric

When Dawnbringer Cleric enters, choose one —
• Cure Wounds — You gain 2 life.
• Dispel Magic — Destroy target enchantment.
• Gentle Repose — Exile target card from a graveyard.

Youthful Knight

Inspiring Overseer

Flying
When this creature enters, you gain 1 life and draw a card.

Omen of the Sun

Flash
When Omen of the Sun enters, create two 1/1 white Human Soldier creature tokens and you gain 2 life.
{2}{W}, Sacrifice Omen of the Sun: Scry 2.

Plains

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

Enchant creature
Enchanted creature gets +2/+2, has first strike, and is a Knight in addition to its other types. (It deals combat damage before creatures without first strike.)

Idyllic Grange

({T}: Add {W}.)
Idyllic Grange enters tapped unless you control three or more other Plains.
When Idyllic Grange enters untapped, put a +1/+1 counter on target creature you control.

Knight's Pledge

Enchant creature
Enchanted creature gets +2/+2.

Shining Armor

Flash
When Shining Armor enters, attach it to target Knight you control.
Equipped creature gets +0/+2 and has vigilance.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Dizzying Swoop

Tap up to two target creatures. (Then exile this card. You may cast the creature later from exile.)

Ardenvale Tactician

Ardenvale Tactician // Dizzying Swoop

Silverflame Ritual

Put a +1/+1 counter on each creature you control.
Adamant — If at least three white mana was spent to cast this spell, creatures you control gain vigilance until end of turn.