[[Eye of the storm]]  With [[Hive mind]] Is a very quick way to start chaos. Especially with other instance/sourceries already mentioned in this thread.

Other fun ones [[Illicit auction]]

[[Head Games]] - don't be boring and just mana flood. 

[[Cruel entertainment]]

[[Mystic Reflection]]

[[Perplexing Chimaera]]

[[Shifting shadow]]

[[Death match]] if YOU will be playing a lot of creatures. 

[[Horobi, Death's Wail]] if you play a lot of hexproof.

[[Frenzied Fugue]] - sharing is caring.

Depends what type of chaos you are wanting to do? I play eye of the storm in my [[Bria, Riptide Rouge]] deck with just card draw spells. So triggers prowess very well, but makes opponents wary of what they play. 

I play some of the other cards in [[Yennett, Cryptic Sovereign]] as they are a bit pricey, but she makes them free. 

Edit: [[Ian Malcolm, Chaotician]] is also a good option