The Odyssey

The Odyssey gets -1/-1 for each creature on the battlefield with power equal to its toughness, and +1/+1 for each permanent on the battlefield with an odd converted mana cost. (One is odd.)
At the beginning of your upkeep, each opponent creates a 1/1 colorless Odyssey creature token for each non-land permanent they control with an even converted mana cost. (Zero is even.)
{1}: Target creature gets +1/-1 or -1/+1 until end of turn.