+2: Untap each creature you control with a +1/+1 counter on it, then you may place an additional +1/+1 counter on each creature untapped this way.
-2: Choose a creature you control. Sacrifice it, then search your library for a creature card with converted mana cost equal to 1 plus the sacrificed creature's converted mana cost, put that card onto the battlefield, then shuffle your library.
-4: You get an emblem with "Creatures you control enter the battlefield with an additional +1/+1 counter"
This probably needs some rewording, but the concept is really cool.