Champs and States

Ionize

Izzet Polarizer

Instant

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

Electrolyze

Legendary Creature — Dragon Wizard

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

Niv-Mizzet, the Firemind

Goblin

Creature — Zombie Shaman

({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.

Rakdos Guildmage

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

Voidslime

Assembly-Worker

Land — Urza's

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

Urza's Factory

Creature — Angel

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

Serra Avenger

Creature — Human Knight

Blood Knight

Creature — Elemental

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

Groundbreaker

Elf Warrior

Creature — Elf Warrior

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

Imperious Perfect

Legendary Creature — Treefolk Shaman

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

Doran, the Siege Tower

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.

Bramblewood Paragon

Land

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