Spawning Pool

This land enters tapped.
{T}: Add {B}.
{1}{B}: This land becomes a 1/1 black Skeleton creature with "{B}: Regenerate this creature" until end of turn. It's still a land. (If it regenerates, the next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Treetop Village

This land enters tapped.
{T}: Add {G}.
{1}{G}: This land becomes a 3/3 green Ape creature with trample until end of turn. It's still a land. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Opal Avenger

When you have 10 or less life, if this permanent is an enchantment, it becomes a 3/5 Soldier creature.

Opal Champion

When an opponent casts a creature spell, if this permanent is an enchantment, it becomes a 3/3 Knight creature with first strike.

Peace and Quiet

Planar Collapse

At the beginning of your upkeep, if there are four or more creatures on the battlefield, sacrifice this enchantment and destroy all creatures. They can't be regenerated.

Purify

Blessed Reversal

You gain 3 life for each creature attacking you.

Radiant, Archangel

Flying, vigilance
Radiant gets +1/+1 for each other creature on the battlefield with flying.

Radiant's Dragoons

Echo {3}{W} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, you gain 5 life.

Radiant's Judgment

Destroy target creature with power 4 or greater.
Cycling {2} ({2}, Discard this card: Draw a card.)

Sustainer of the Realm

Flying
Whenever this creature blocks, it gets +0/+2 until end of turn.

Tragic Poet

{T}, Sacrifice this creature: Return target enchantment card from your graveyard to your hand.

Anthroplasm

This creature enters with two +1/+1 counters on it.
{X}, {T}: Remove all +1/+1 counters from this creature and put X +1/+1 counters on it.

Archivist

Aura Flux

Other enchantments have "At the beginning of your upkeep, sacrifice this enchantment unless you pay {2}."

Urza's Legacy