Ugin's Conjurant

This creature enters with X +1/+1 counters on it.
If damage would be dealt to this creature while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from this creature.

Celestial Kirin

Flying
Whenever you cast a Spirit or Arcane spell, destroy all permanents with that spell's mana value.

Oyobi, Who Split the Heavens

Flying
Whenever you cast a Spirit or Arcane spell, create a 3/3 white Spirit creature token with flying.

Kami of False Hope

Sacrifice this creature: Prevent all combat damage that would be dealt this turn.

Rescuer Chwinga

Flash
Natural Shelter — When this creature enters, you may return another permanent you control to its owner's hand.

Nikko-Onna

When this creature enters, destroy target enchantment.
Whenever you cast a Spirit or Arcane spell, you may return this creature to its owner's hand.

Ethereal Haze

Prevent all damage that would be dealt by creatures this turn.

Blessed Breath

Target creature you control gains protection from the color of your choice until end of turn.
Splice onto Arcane {W} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Selfless Spirit

Flying
Sacrifice this creature: Creatures you control gain indestructible until end of turn.

Omarthis, Ghostfire Initiate

Omarthis enters with X +1/+1 counters on it.
Whenever you put one or more +1/+1 counters on another colorless creature, you may put a +1/+1 counter on Omarthis.
When Omarthis dies, manifest a number of cards from the top of your library equal to the number of counters on it.