Bulk Up

Double target creature's power until end of turn.
Flashback {4}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Plains

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Clockwork Percussionist

Haste
When Clockwork Percussionist dies, exile the top card of your library. You may play it until the end of your next turn.

Kellan, Planar Trailblazer

{1}{R}: If Kellan is a Scout, it becomes a Human Faerie Detective and gains "Whenever Kellan deals combat damage to a player, exile the top card of your library. You may play that card this turn."
{2}{R}: If Kellan is a Detective, it becomes a 3/2 Human Faerie Rogue and gains double strike.

Glorifier of Suffering

When Glorifier of Suffering enters, you may sacrifice another creature or artifact. When you do, put a +1/+1 counter on each of up to two target creatures.

Mountain

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.