Daybreak Charger

When Daybreak Charger enters, target creature gets +2/+0 until end of turn.

Celestial Unicorn

Whenever you gain life, put a +1/+1 counter on Celestial Unicorn.

Regal Unicorn

Valorous Steed

Vigilance (Attacking doesn't cause this creature to tap.)
When Valorous Steed enters, create a 2/2 white Knight creature token with vigilance.

Mesa Unicorn

Inspiring Unicorn

Whenever Inspiring Unicorn attacks, creatures you control get +1/+1 until end of turn.

Prized Unicorn

All creatures able to block Prized Unicorn do so.

Blessed Sanctuary

Prevent all noncombat damage that would be dealt to you and creatures you control.
Whenever a nontoken creature you control enters, create a 2/2 white Unicorn creature token.

Rider in Need

Create a 2/2 white Knight creature token with vigilance. (Then exile this card. You may cast the creature later from exile.)

Lonesome Unicorn

Lonesome Unicorn // Rider in Need

Emiel the Blessed

{3}: Exile another target creature you control, then return it to the battlefield under its owner's control.
Whenever another creature you control enters, you may pay {G/W}. If you do, put a +1/+1 counter on it. If it's a Unicorn, put two +1/+1 counters on it instead. ({G/W} can be paid with either {G} or {W}.)

Captivating Unicorn

Constellation — Whenever an enchantment you control enters, tap target creature an opponent controls.

Ronom Unicorn

Sacrifice Ronom Unicorn: Destroy target enchantment.

Good-Fortune Unicorn

Whenever another creature you control enters, put a +1/+1 counter on that creature.

Zebra Unicorn

Whenever Zebra Unicorn deals damage, you gain that much life.

Brightmare

When Brightmare enters, tap up to one target creature. You gain life equal to that creature's power.

Lathiel, the Bounteous Dawn

Lifelink
At the beginning of each end step, if you gained life this turn, distribute up to that many +1/+1 counters among any number of other target creatures.