Skyclave Apparition

When this creature enters, exile up to one target nonland, nontoken permanent you don't control with mana value 4 or less.
When this creature leaves the battlefield, the exiled card's owner creates an X/X blue Illusion creature token, where X is the mana value of the exiled card.

Venerable Warsinger

Vigilance, trample
Whenever this creature deals combat damage to a player, you may return target creature card with mana value X or less from your graveyard to the battlefield, where X is the amount of damage this creature dealt to that player.

Hofri Ghostforge

Spirits you control get +1/+1 and have trample and haste.
Whenever another nontoken creature you control dies, exile it. If you do, create a token that's a copy of that creature, except it's a Spirit in addition to its other types and it has "When this token leaves the battlefield, return the exiled card to its owner's graveyard."

Guardian of Faith

Flash
Vigilance
When this creature enters, any number of other target creatures you control phase out. (Treat them and anything attached to them as though they don't exist until their controller's next turn.)

Selfless Spirit

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