Name:Eldritch Evolution
ManaCost:1 G G
Types:Sorcery
A:SP$ ChangeZone | Cost$ 1 G G Sac<1/Creature> | Origin$ Library | Destination$ Battlefield | ChangeType$ Creature.cmcLEX | ChangeNum$ 1 | References$ X | SubAbility$ DBChange | AILogic$ SacAndUpgrade+SacWorst | StackDescription$ SpellDescription | SpellDescription$ Search your library for a creature card with converted mana cost X or less, where X is 2 plus the sacrificed creature's converted mana cost. Put that card onto the battlefield, then shuffle your library. Exile CARDNAME.
SVar:DBChange:DB$ ChangeZone | Origin$ Stack | Destination$ Exile 
SVar:X:Sacrificed$CardManaCost/Plus.2
SVar:AIPreference:SacCost$Creature
SVar:Picture:http://www.wizards.com/global/images/magic/general/eldritch_evolution.jpg
Oracle:As an additional cost to cast Eldritch Evolution, sacrifice a creature.\nSearch your library for a creature card with converted mana cost X or less, where X is 2 plus the sacrificed creature's converted mana cost. Put that card onto the battlefield, then shuffle your library. Exile Eldritch Evolution.