Mirrodin, Plane of Machines

—During your upkeep, roll a d20 :
1 : Put a 7/7 Myr creature token with haste into
play under your control.
2 - 5: Play a random card from the generator pile without paying for its mana cost.
6 - 15: Put a +1/+1 counter on target creature.
16 - 19: Play a random card from the disposal pile without paying for its mana cost.
20 : Opponents destroy target permanent you
control. Then, create X treasure tokens, where X
was its converted mana cost.