This looks fun. It might be a little slow, but I'm not too sure about this. I think Mosswort Bridge could work in this deck very well. Also, Sanctum of Ugin might be quite cool for you.

Both of those lands have some juicy promise. Love the fact they shore up the occasional problem of not finding fatties to play in later turns (which is why there's so much draw in the deck). But the reason why I'm wary of using them is the first thing you said: the deck can be slow. Both lands really don't do anything until after I'm casting the big creatures, and then they really shine. But I discovered that (God draw aside) I'm usually waiting until turn 4-5 to play out my first monster, and sometimes that's just too late.

I do love the idea of suddenly putting out It That Betrays at instant speed for one mana though. Or finding more fatties without much hassle. I'll probably gold fish with those lands subbed in to see how it draws.

Maybe Fierce Empath to search for fatties?

Fierce Empath something else to consider, although not sure what I'd swap it in for. Maybe Preordain, but I like having the choice to either search for early game ramp or use it to dig for fatties later. Another idea is to put in a couple more Conduit of Ruins instead, allowing to search up the eldrazi while making it easier to cast them and being reliable threats themselves.

Why would you do this? +1 from me. I love the great prophet so this deck is just great.

If you own this deck, how many friends do you have left?

t minus 4 days when I build the deck proper and get to play it, actually, so haven't had the chance to punch my friends in the head with eldrazi yet. But Doom Blades, Counterspell, and the occasional Cyclonic Rift abound, so I think they won't run screaming into the night. But we'll see, turn 3-5 eldrazi can be pretty effective...

And I did this because Prophet of Kruphix has a fantastic, powerful effect that got banned from the only format that ever used it. And I want to play prophet, dang it.