mtg, mtg cards, magic the gathering, gaming, geeks
Changeling cards are totally your friend, since they're all creature types at all times. You already have Shapesharer , but I'm particularly fond of Mirror Entity . Clone is a staple creature in all of my blue decks, not only because it's useful for tribal purposes, but because it can copy my opponents' biggest bruisers, and also because it can kill generals.
If you're going to be sacrificing merfolk, and your token production isn't what you want it to be, perhaps card:Marshal's Anthem will be helpful?
Relearn has treated me very well in every deck I've shoved it into. Blue control EDH decks tend to run out of steam in multi-player, and Relearn helps keep the gears of controlly obnoxiousness turning.
A lot of your creatures are wizards. Perhaps Sage of Fables would be a fun addition?
I also love Silvergill Douser . It's one of the pieces of a Merfolk/Faerie/Wizard deck I built a while ago, and whenever it comes out, people need to Deal With It Somehow.
Hope my (usual) braindumpy suggestions are useful!
Okay, now there's potential for infinite life, damage, and creatures... combination of Stonybrook Schoolmaster enchanted with Psionic Gift , with Intruder Alarm in play allows for infinite damage and creatures... throw in a Judge of Currents for infinite life, and a Lullmage Mentor for infinite counterspells and insanity abounds.
I've seen your deck. From my point of view you have lot of cards, it's really hard when you see all the Merfolks! I've made a Merfolk deck myself, it's called deck:merfolks-fairy-tale, maybe you can check it out.
It's basically the same, but i took longer to choose the Merfolks i wanted to use. Most of them are Rare cards, some of them i'm still missing.