First and foremost, I think manifest is severely underrated at the moment. Manifest, is a touch random at times, and while people may want to run Lens of Clarity to peek, I think that's crazy. Here's why Manifest is good:
Card Advantage. Lets say I manifest a land down on my endstep with a Whisperwood elemental. My opponent doesn't know its a land and potentially may use a removal to target it. Not only is he wasting valuable cards, I'm getting use out of mine in unexpected ways.
Denying Information: In a format with Thoughtsieze and Courser of Kruphix, most opponents may feel like they have a lot of information and can make high efficiency decisions. Manifest denies this information to them constantly.
Tricks and Unexpected crazy. Its a little silly, but I'm running a ton of creatures. All of these, when manifested are what I would consider tricks. An opponent might attack in with a Siege Rhino, thinking I might have to gang block him. Nope. I assign my blocker. Before combat damage resolves -- at faster than instant speed -- I flip over a Hooded Hyrda for GG, and good bye Rhino. Its better than a Giant Growth.
Value: EVERY CARD IN THIS DECK IS POTENTIALLY A BEAR.
So, here is my deck, which I built with JakeHarlow. A ton of creatures that can be used by manifest well a few manifest enablers, and a utility package.
On some choices. I included Illusory Angel b/c if I manifest it, I skip the ETB requirement and more importantly, I would loooooove to flip it to block a Stormbreath Dragon. Surprise dummy.
Hooded Hydra is a must have in a manifest deck, IMHO, you can get more utility out of it than a Goyf
Frost Walker seems weak, but upon closer inspection, as a manifest card, I can sneak it in for four, trade block for quite a bit of Standard's creatures, and it activates Ferocious very early.
Master of Pearls is on the side board because it is definitely a Round 2 surprise that is easy enough to splash.
Gimme your thoughts.