Tormenting Madness

Convoke (Each creature you tap while playing this spell reduces its cost by {1} or by one mana
of that creature's color)
1-3= Destroy target creature then it's owner
draws a card & you must discard a card.
4-8= Same as above except you don't discard.
9-14= Same as above except they discard a card.
15-20= Same as above except you draw a card.