Let's start with the 5 prerelease rares:


Silent Centinel
Creature - Archon (rare)

Flying
Whenever ~ attacks, you may return target enchantment card from your graveyard to the battlefield.

4/6

Mediator of the Ideal
Creature - Sphinx (rare)

Flying
Inspiration - Whenever ~ untaps, reveal the top card of your library. If its an artifact, creature, or land card you may put it onto the battlefield with a manifestation counter on it. It is an enchantment in addition to its other types.

4/5

Devourer of Hope
Creature - Demon (rare)

Flying
, Sacrifice another creature: Regenerate ~.
, Sacrifice two other creatures: Destroy target creature.

6/4

Firestir Dragon
Creature - Dragon (rare)

Flying
: ~ deals 1 damage to target creature. That creature can't block this combat. Activate this ability only if ~ is attacking.

5/4

Wild Devastating Nessian
Creature - Hydra (rare)

Tribute 6 (As this creature enters the battlefield, an opponent of your choice may put 6 +1/+1 counter on it.)
When ~ enters the battlefield, if the tribute wasn't pay, you may have ~ fight another target creature.

6/6