Card I would definately include:
Intruder Alarm (omg combo)
Meloku the Clouded Mirror (omg amazing + combo)
Brainfreeze (game-ender)
Vesuvan Shapeshifter (also amazing)
Some Merfolk Wizards to consider a mini-theme:
Merrow Harbinger (mystical for a merfolk)
Drowner Initiate (mill)
Drowner of Secretes (mill)
Sage of Fables (card draw + wizard pumper)
Sea Scryer (mana)
Surgespanner (somewhat expensive capsize~esq card)
Possibly add in another infinite mana combo too, like
Basault Monolith / Grim Monolith
Power Artifact
I've had some of that stuff in the deck before - Sage of Fables, Surgespanner, Sea Scryer, Meloku, Brain Freeze. Most of it was cut because it didn't do enough on its own. Sea Scryer was fun, but slow, and Meloku was broken, but it's ability wasn't what I wanted to be doing (ever. Land drops all day long.) I cut Brain Freeze because it's most common use was Imprint on Chrome Mox. I've considered Power Artifact, but haven't really committed to it, so maybe it's good. I get infinite mana from Academy and/or Tidespout pretty easily, so I'd have to test it. It's hard to test at all, though, because this deck is really like bringing a shotgun to a knife fight. People tend to focus on killing you, which takes most of the fun out of it anyway. This is my "once in a while" deck.
