Unpredictable Flux

Unpredictable Flux enters the battlefield with 3
flux counters on it.
Everytime you cast an instant or sorcey add a
flux counter to Unpredictable Flux. Remove
a flux counter everytime an opponent casts an
instant or sorcery.
Remove a flux counter from Unpredictable Flux:
You may cast spells this turn at instant speed.