Dorian, In-finite Gambler

At the beginning of your upkeep, roll a d20
1-5: Split second, Flip a coin for each creature
on the battlefield, destroy the creature on a
losing flip.
6-10: Gain control of a random creature, and
give control of a random creature.
11-17: All players discard their hands and draw a
new 7
16-20: All players discard their hands, and
switch their library and graveyard, each player
then shuffles their new library