Joker, Agent of Chaos

Instant spells you control cost {1} less to cast
Anytime and opponent casts a spell that targets you
or permanents you control, create a mayhem creature token.
Anytime you cast an instant spell you may {t} Joker, Agent of Chaos, if you do, create a x/x explosive artifact token where x is equal to the instants mana value.

Anytime another player casts an instant spell flip coin, if heads, you may exile the top card of your library. You may cast that card until end of turn. If tails, draw a card.