Mirror March

Whenever a nontoken creature you control enters, flip a coin until you lose a flip. For each flip you won, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.

Purphoros, Bronze-Blooded

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Other creatures you control have haste.
{2}{R}: You may put a red creature card or an artifact creature card from your hand onto the battlefield. Sacrifice it at the beginning of the next end step.

Sundial of the Infinite

{1}, {T}: End the turn. Activate only during your turn. (Exile all spells and abilities from the stack. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Hoarding Dragon

Flying
When Hoarding Dragon enters, you may search your library for an artifact card, exile it, then shuffle.
When Hoarding Dragon dies, you may put the exiled card into its owner's hand.

Stalking Vengeance

Haste
Whenever another creature you control dies, it deals damage equal to its power to target player or planeswalker.

Dragon Mage

Flying
Whenever Dragon Mage deals combat damage to a player, each player discards their hand, then draws seven cards.

Iron Myr

Ryusei, the Falling Star

Flying
When Ryusei, the Falling Star dies, it deals 5 damage to each creature without flying.

Clone Shell

Imprint — When Clone Shell enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom of your library in any order.
When Clone Shell dies, turn the exiled card face up. If it's a creature card, put it onto the battlefield under your control.

Bloodfire Colossus

{R}, Sacrifice Bloodfire Colossus: It deals 6 damage to each creature and each player.

Cauldron of Souls

{T}: Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Irencrag Feat

Add seven {R}. You can cast only one more spell this turn.

Knollspine Dragon

Flying
When Knollspine Dragon enters, you may discard your hand and draw cards equal to the damage dealt to target opponent this turn.

Chaos Maw

When Chaos Maw enters, it deals 3 damage to each other creature.

Spawn of Thraxes

Flying
When Spawn of Thraxes enters, it deals damage to any target equal to the number of Mountains you control.

Feldon of the Third Path

{2}{R}, {T}: Create a token that's a copy of target creature card in your graveyard, except it's an artifact in addition to its other types. It gains haste. Sacrifice it at the beginning of the next end step.