Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice this enchantment.
{B}: This enchantment deals 1 damage to each creature and each player.

Phyrexian Scriptures

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Put a +1/+1 counter on up to one target creature. That creature becomes an artifact in addition to its other types.
II — Destroy all nonartifact creatures.
III — Exile all opponents' graveyards.

Death-Rattle Oni

Flash
This spell costs {2} less to cast for each creature that died this turn.
When this creature enters, destroy all other creatures that were dealt damage this turn.

Last Laugh

Whenever a permanent other than this enchantment is put into a graveyard from the battlefield, this enchantment deals 1 damage to each creature and each player.
When no creatures are on the battlefield, sacrifice this enchantment.

Deathbringer Regent

Flying
When this creature enters, if you cast it from your hand and there are five or more other creatures on the battlefield, destroy all other creatures.

Perilous Vault

{5}, {T}, Exile this artifact: Exile all nonland permanents.

Worldslayer

Whenever equipped creature deals combat damage to a player, destroy all permanents other than this Equipment.
Equip {5} ({5}: Attach to target creature you control. Equip only as a sorcery.)

Ugin, the Spirit Dragon

+2: Ugin deals 3 damage to any target.
−X: Exile each permanent with mana value X or less that's one or more colors.
−10: You gain 7 life, draw seven cards, then put up to seven permanent cards from your hand onto the battlefield.

Havoc Demon

Flying
When this creature dies, all creatures get -5/-5 until end of turn.

Oblivion Stone

{4}, {T}: Put a fate counter on target permanent.
{5}, {T}, Sacrifice this artifact: Destroy each nonland permanent without a fate counter on it, then remove all fate counters from all permanents.

Whiptongue Hydra

Reach
When this creature enters, destroy all creatures with flying. Put a +1/+1 counter on this creature for each creature destroyed this way.

Bane of Progress

When this creature enters, destroy all artifacts and enchantments. Put a +1/+1 counter on this creature for each permanent destroyed this way.

Pernicious Deed

{X}, Sacrifice this enchantment: Destroy each artifact, creature, and enchantment with mana value X or less.

Nevinyrral's Disk

This artifact enters tapped.
{1}, {T}: Destroy all artifacts, creatures, and enchantments.

Boompile

{T}: Flip a coin. If you win the flip, destroy all nonland permanents.

Reiver Demon

Flying
When this creature enters, if you cast it from your hand, destroy all nonartifact, nonblack creatures. They can't be regenerated.