­Maelstrom Archangel + Maelstrom Nexus + Valkri. I think the archangel's flavor text applies to this, as well.

Turbulence is so similar to Cascade.

It's much easier to control, though. No more accidental Borderposts. Of course, some people like that element of chance..

I wanted to use a mechanic similar to cascade or ripple, but enough different to stand out as a new mechanic. I also wanted it to be chaotic. You're both right in that it is very derivative and it isn't very random. Suggestions on what to do?

First of all, I don't think there's anything 'wrong' with how your doing things. That said, how about this?:

Turbulence (When you cast this spell, look at the top ten cards of your library. You may cast one of those cards without paying its mana cost if it has the same converted mana cost as this spell. Shuffle the rest of the cards and put them on the bottom of your library.)

This way you have an element of chance (which, unfortunately, also supplies a chance of completely whiffing), but also an element of control, since you can choose which 5cc spell you want to cast. The extra benefit is that, by using this method, you're convincing players that they want to front-load a specific number in an attempt to get Turbulence to hit more often (I consider that a plus, at least. Increases archetype variance). Also, this takes a dagger to decks that want to abuse Turbulence to combo out. If you can't guarantee that Turbulence will give you Early Harvest, Spike is less likely going to try to win with the deck. Still a good option for Johnny, though. Johnny doesn't need to win, to win.