Chromium, the Mutable
{4}{W}{U}{B}
Legendary Creature -- Elder Dragon
7/7
Flash
~this~ can't be countered.
Flying
Discard a card: Until end of turn, ~this~ becomes a Human with base power and toughness 1/1, loses all abilities, and gains hexproof. It can't be blocked this turn.
Writ of Passage
{U}
Enchantment -- Aura
Enchant creature
Whenever enchanted creature attacks, if its power is 2 or less, it can't be blocked this turn.
Forecast -- {1}{U}, Reveal ~this~ from your hand: Target creature with power 2 or less can't be blocked this turn. (Activate only during your upkeep and only once each turn.)