Thanks for all the suggestions!

@Ziembski I feel that Dream Chisel isn't impactful enough because a lot of my creatures do not have morph. Ill try it out though.

@Barsan Thanks, I am adding it now.

@SirSh4ggy I am trying to avoid one-off manifest cards because they don't do a lot in the long run. Flicker cards don't really do morph cards justice, because I cant attack with a face down creature and hit with a face up creature. They are good at flipping unwanted manifested creatures though. I think I will try out Lightform and Deadeye Navigator for the extra life gain and reusable flicker.

Exxie97 actually, since turning them face up doesn't use the stack, and after blockers are declared you're able to instant speed flicker, they can hit as their flipped form. Snapcaster Mage gets em back for you, and a 10-drop eldrazi for 3 is pretty good.

@Exxie97 He is confusing flipping and flickering. Flickered Creatures leave combat and have summoning sickness, Flipped creatures do not.

Roon of the Hidden Realm exists in your colors and can be used to unflip specific creatures after your opponents swing out, as a means of defense, or to repeat powerful ETB Triggers such as Ixidron and with Voidslime's stifle effect, or Sundial of the Infinite (Which can also prevent detrimental ETB effects) you can permanently exile creatures... even Commanders.

Phage the Untouchable in an Esper capable deck kind of begs for a Fractured Identity doesn't it? Especially considering you run Eater of Days.

Disallow is a strict mana cost improvement on Voidslime

I absolutely hate that Felidar Sovereign is allowed in EDH. At least a Phage Textwin is risky.

@Barsan Thanks for clearing that up, the rules on morph are a bit strange so I wasn't sure.

Wow, never even heard of Fractured Identity, Ill definitely try and find a spot for this. (It's so mean with Phage the Untouchable, I love it XD).
Roon of the Hidden Realm is a interesting one. He does provide a lot of useful utility, but I'm not sure if I have enough cards that work well with him to make him worth it. I'll definitely give him a try though.
Sundial of the Infinite is kinda in the same boat as Roon of the Hidden Realm (obviously it would work better if I included both of them). I do like how easily accessible it is, I think almost all my tutors can hit a two mana artifact.
I think I'll end up just cutting Voidslime. Thanks for the note on Disallow though.
I know Felidar Sovereign is cheesy in EDH, but the fact that my opponents always have to look out for it s partly why I use it.

Thanks again for all the great suggestions.

Also of Note:Zoetic Cavern feels like it belongs, optional and weird mana acceleration is kind of cool on it's own but with other scary morph cards it's a threat.

Vanish into Memory is also a neat card for card draw and the magic it works for manifest cards. If you hit a token or a non creature flipped card you draw 2 and the toughness and discard are 0. Hit an opponent's 20/20 Avatar... good times. And if worst comes to worst you hit your opponent's bomb on their endstep and play out your hand before the discard on yours.

Dark Depths might be good in your deck if you could manifest it and turn it face up but Thing in the Ice  ^Flip would really appreciate the flip. It would sit there waiting for you to cast an instant or sorcery to transform it and bounce everybody's creatures.

Sorry about all the comments, I really appreciate themed decks and yours is full of potential.