Kurboros,the shadow lord

+2: Sacrifice a creature to create an x/x token creature nammed shadow hound,x being the converted mana cost of the sacrificed creature +1.
+4: Lose x life to create an x/x shadow token nammed servant of the shadow.
-20: Create Ashorad,an legendairy 15/15 shadow horror with trample,then sacrifice all your shadow to add their total power and toughness to Ashorad.