So... tonight I sit down to my first game of R'lyeh Dreamlands and LOVE it. I can't begin to tell you how great that Domain effect is at Dominion 10. Fodder aplenty with tons of Void Gate spawns showing up all over your Dominion free of charge (without Summoning mishaps even!) You also get a ton of free commanders, albeit insane ones who Ftaghn a lot.
But HERE is the REALLY cool part...
...
...
wait for it...
...
So, one of my insane hybrid cultist leaders was sitting around, doing insane things, when he decides to "Become Prophet". "Aw, how cute," I say. But I already have a Starspawn Prophet, so I figure it's just a wasted action. Then, the next turn, I see a proclamation stating that said cultist has become my Prophet! WHA? I go and check out my Starspawn Prophet. Yep, still there.
So, yes. I'm not sure if it's a bug or not, but R'lyeh Dreamlands is capable of having multiple Prophets.
They win.
