Breach the Multiverse

Each player mills ten cards. For each player, choose a creature or planeswalker card in that player's graveyard. Put those cards onto the battlefield under your control. Then each creature you control becomes a Phyrexian in addition to its other types.

Sepulchral Primordial

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
When Sepulchral Primordial enters, for each opponent, you may put up to one target creature card from that player's graveyard onto the battlefield under your control.

Overwhelming Stampede

Until end of turn, creatures you control gain trample and get +X/+X, where X is the greatest power among creatures you control.

Invert the Skies

Creatures your opponents control lose flying until end of turn if {G} was spent to cast this spell, and creatures you control gain flying until end of turn if {U} was spent to cast this spell. (Do both if {G}{U} was spent.)

Sleep

Tap all creatures target player controls. Those creatures don't untap during that player's next untap step.

Insurrection

Untap all creatures and gain control of them until end of turn. They gain haste until end of turn.

Taunt from the Rampart

Goad all creatures your opponents control. Until your next turn, those creatures can't block. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Archetype of Imagination

Creatures you control have flying.
Creatures your opponents control lose flying and can't have or gain flying.

Mass Mutiny

For each opponent, gain control of up to one target creature that player controls until end of turn. Untap those creatures. They gain haste until end of turn.

Tooth and Nail

Choose one —
• Search your library for up to two creature cards, reveal them, put them into your hand, then shuffle.
• Put up to two creature cards from your hand onto the battlefield.
Entwine {2} (Choose both if you pay the entwine cost.)

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Dragon Throne of Tarkir

Equipped creature has defender and "{2}, {T}: Other creatures you control gain trample and get +X/+X until end of turn, where X is this creature's power."
Equip {3}

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.