Ionize

Electrolyze

Izzet Polarizer

Electrolyze deals 2 damage divided as you choose among one or two targets.
Draw a card.

Doran, the Siege Tower

Each creature assigns combat damage equal to its toughness rather than its power.

Bramblewood Paragon

Each other Warrior creature you control enters with an additional +1/+1 counter on it.
Each creature you control with a +1/+1 counter on it has trample.

Mutable Explorer

Mutavault

{T}: Add {C}.
{1}: This land becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Niv-Mizzet, the Firemind

Flying
Whenever you draw a card, Niv-Mizzet deals 1 damage to any target.
{T}: Draw a card.

Rakdos Guildmage

Goblin

({B/R} can be paid with either {B} or {R}.)
{3}{B}, Discard a card: Target creature gets -2/-2 until end of turn.
{3}{R}: Create a 2/1 red Goblin creature token with haste. Exile it at the beginning of the next end step.

Voidslime

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Assembly-Worker

Urza's Factory

{T}: Add {C}.
{7}, {T}: Create a 2/2 colorless Assembly-Worker artifact creature token.

Serra Avenger

You can't cast Serra Avenger during your first, second, or third turns of the game.
Flying, vigilance

Blood Knight

Groundbreaker

Trample, haste
At the beginning of the end step, sacrifice this creature.

Imperious Perfect

Elf Warrior

Other Elves you control get +1/+1.
{G}, {T}: Create a 1/1 green Elf Warrior creature token.

Champs and States