Tides of Chaos

At the beginning of your upkeep, sacrifice Tides
of Chaos unless you pay {u}{r}. If you do, roll a
d20.
1-5| Discard a random card from your hand.
6-10| The first time you cast and instant or
sorcery spell this turn, you may cast it as though
it had overload {1}{u}{r}.
11-15| The first spell you cast this turn cannot be countered.
16-20| Tides of Chaos deals 5 damage to each
player and permanent on the battlefield.