I think I agree its better to keep 3 Otyugh's just so you draw one faster. I actually had a game last night where ALL 3 Otyugh's were my last 3 cards of the deck. Since I had no eternity I was kind of freaking out, but somehow I won (I forget which God it was now... was not Miracle or Incarnate, I think it was Chaos Lord or Morte). Since Otyugh is a main part of this deck I was impressed that the deck was still versatile enough to win without it (my Fallen Druids did not mutate my fireflies with any creature-controlling abilities either). Basically the fact that I had 2 rain of fires for creature control and supplying my bonewall allowed me to win without the Otyugh. But in any case, it is not an experience I want to increase by having only 2 Otyugh's. And with 3 you usually get one by the time you have 4 Gravity Quantum which is a great help in staying in control and speeding up the game.
Thanks for the tips regarding Seism. I had not noticed exactly at what point he rewinded the Otyugh, so I will try to keep him from growing that big (then again, if in a Seism game I am able to eat more than 3 creatures to begin with it probably means I've gotten enough quantums to win). I had also not thought of not eating his gnomes, perhaps I will try that.
I did try one variation where I just kept all the same cards and added one PU. Once I made this change I played about 5 games, and for 3 of them I got absolutely terrible draws and lost (I lost to MIRACLE and INCARNATE in back to back games!). In both I just had strange draws where ~20 cards into my deck I still had not drawn sundials or creature control (Otyugh/firestorm or even a druid I think). In all the games I had a PU in my hand which was doing me no good (I could PU Miracle's 18/18 dragon but that won't make him kill me any slower). I couldn't help but think, "if only this PU wasn't in my deck I very well may have drawn that sundial on my last turn." And then even in the games I won, the PU was never that useful. Since there are multiple copies of all creatures in the deck, you usually don't need to PU your own that badly. PU-ing some 15/15 thing is always nice, but it almost never wins the game for me. So I decided since adding a PU a) expands your deck even bigger when the number of towers you have already is walking a thin line, b) will very rarely be the difference between a winning and losing game vs the AI and c) this deck is already reasonably fast as far as false gods go, it didn't seem worth it. And there aren't really any cards I would want to take out. I like the number of firestorms, Otyugh, Hourglasses in there for sure... I also would not want to take out a Fallen Druid since having only 1 with them being so easy to kill is annoying. And Druids are also great for speeding the game up. If you wanted to replace a card for the PU I would probably go for a FFQ, but I don't think it would end up being worth it (with only 1 FFQ you would often not draw it until late game, which could slow some games down considerably since the fireflies are basically your only unit with any attack power aside from mutations)
I'm not sure how many games I've played with it so far (too many considering its only been a couple days!), but I'm still lovin it. Rainbow and Hermes I have not found to be too bad, though they can occassionally win. Really though it seems like going into each game I expect to basically always win, unless I am facing Seism who I lose to more than I beat. But I'd rather just lose those games against Seism than change the deck around and add cards that are more or less useless against other gods.
If on the rare chance I try some variation that does work, I will let you know! Maxwell's demon is another one that I would be interested in trying to fit in if possible since the mark is Entropy, but like PU it may just prove to not be vital enough to warrant adding. With the rain of fire's the Demon would work great and may be nice at killing some of Seism/Rainbow/Herme's creatures that are too big to eat normally (they are also still just as useful after suffering an opponents rain of fire, which is nice as well). The demon is perhaps one that an Otyugh could be replaced with since it serves basically the same purpose. Disadvantages are if you happened to start with 2 Druids and a Demon in your hand, it would probably take quite some time to play them all. Though then again Druids usually aren't that useful in the first few turns of the game anyway. I think I will try that next time (replace 1 Otyugh with 1 Demon) and see how it goes.