I don't have too much experience playing Isperia as I just recently built one myself, but I would argue that the cards that have your opponents reveal their hands are just not worth the space in your deck. A much more reliable way of getting the tutoring to hit for me has been using bounce spells. Not only does it make sure you get the tutor affect if you connect, but it also keeps nasty permanents off the board until you can get a flier to help you deal with that threat. I don't have access to my list at the moment so I can't thing of much to help you but capsize, riftwing cloudskate (tutorable), and even crystal shard are decent bounce effects. One flier that I have found good is deathless angel, especially when you can use the ability to protect your admonition angel.
Marshal's Anthem might be decent here. Recursion plus pump seems good. Rhys the Redeemed might be worth a look as well. I like that you are using Kyren Negotiations. That card probably is nuts with Rith.
Nice Momir list! Based on the cards in your current list, i'd have to say that you are gearing your list towards a control momir strategy rather than the aggro or combo versions. Here are some cards that you may like for your build.
Teferi, Mage of Zhalfir - pretty busted with Seedborn Muse. The combination gives you pseudo extra turns and can very quickly take over a table in even a large multiplayer game.
Oblivion Stone - never hurts to have a second disk effect.
Blatant Thievery - great way to turn the entire table against you.
Familiar's Ruse - this one is probably only REALLY good if you decide to add Teferi as you can have a soft counterspell lock against the entire table with seedborn muse, teferi, eternal witness, and familiar's ruse
Neurok Stealthsuit - because people like to kill your important creatures. This card is pretty bonkers with a seedborn muse out.
Duplicant - while it doesn't play nice with your general, its still solid since you can at least tutor for it.
Joraga Treespeaker - solid in the early game since he can get your general online by turn 3 and still pretty decent late game since you can use it as a cheap tutor and since a fair number of creatures in your list are elves (including Momir Vig!) you can have some crazy mana late into the game as well.
Vesuvan Shapeshifter + Brine Elemental and/or Winter Orb - While these cards are considered DBish by some, they certainly are powerful. The fun thing about winter orb is that as long as you have seedborn muse, you don't even suffer its drawback.
If you do decide to go back to using aluren / cloudstone curio combination, I would suggest Cloud of Faeries and Pestermite. Cloud of Faeries will give you infinite mana and Pestermite can soft lock unprepared opponents. Hope this helps!
While I totally agree with the above posters that MBC is the way to go, I would like to see a tribal build. But rather than do the obvious thing and go vampires, go MB SHAMANS!
if you decide on running seedborn muse in your list I would recommend running winter orb as well. It can come down rather quick and is quite devastating to a large number of strategies.
I always found leyline of singularity as the ultimate LOLZ solution for tokens. Its so classic when you bust it out on someone who has never seen it before. Anyways for your deck, midnight banshee might be worthy of consideration. While admittedly slow, it is pretty nasty against small creatures and is definitely threatening to many other creatures if it is left alone. For more immediate action soul snuffers is pretty solid.
First of all, let me say that I like your list. I have a Child of Alara EDH deck as well and I see a lot of similarities between my list and your list. I'm curious to know how the counters in your decklist have worked for you. I have two counters in my decklist (mystic snake and draining whelk) and those have worked out well for me since they are good with the instant speed reanimation. One other counter I would suggest is familiar's ruse. I have that that card in my momir vig deck and it is very powerful in conjunction eternal witness or mnemonic wall, its also extremely annoying when you have seedborn muse and teferi down too.
How exactly did you still have mana left to cast Ulamog after Emrakul wiped out six of your permanents?
Because unless you had creatures or something else out, that's a loss of six mana sources, which would result in you dropping back down to 5 mana from your initial 11.
Maybe it was a multiplayer game and the Bribery player attacked someone else
One creature I have found very useful in my Thraximundar deck has been Ink-eyes, Servant of Oni. Thrax clears the way and provides Ink-eyes with plenty of targets.
I always liked using guile with dovescape. While not an instant kill, you gain control of all non-creature spells and make any number of flying 1/1s in the process. Enchanted Evening and Aura Thief is a pretty sweet combo.
Cauldron of Souls seems like it would be pretty nuts with Horobi, essentially you plague wind every turn. Seems like a pretty decent card on its own as well.
Teferi, Mage of Zhalfir - pretty busted with Seedborn Muse. The combination gives you pseudo extra turns and can very quickly take over a table in even a large multiplayer game.
Azami, Lady of Scrolls and/or Arcanis the Omnipotent and/or Enclave Cryptologist - tutorable card draw, seedborn muse makes all these cards, particularly the first two, very powerful card advantage engines.
Oblivion Stone - never hurts to have a second disk effect.
Blatant Thievery - great way to turn the entire table against you.
Familiar's Ruse - this one is probably only REALLY good if you decide to add Teferi as you can have a soft counterspell lock against the entire table with seedborn muse, teferi, eternal witness, and familiar's ruse
Neurok Stealthsuit - because people like to kill your important creatures. This card is pretty bonkers with a seedborn muse out.
Duplicant - while it doesn't play nice with your general, its still solid since you can at least tutor for it.
Joraga Treespeaker - solid in the early game since he can get your general online by turn 3 and still pretty decent late game since you can use it as a cheap tutor and since a fair number of creatures in your list are elves (including Momir Vig!) you can have some crazy mana late into the game as well.
Vesuvan Shapeshifter + Brine Elemental and/or Winter Orb - While these cards are considered DBish by some, they certainly are powerful. The fun thing about winter orb is that as long as you have seedborn muse, you don't even suffer its drawback.
If you do decide to go back to using aluren / cloudstone curio combination, I would suggest Cloud of Faeries and Pestermite. Cloud of Faeries will give you infinite mana and Pestermite can soft lock unprepared opponents. Hope this helps!
Maybe it was a multiplayer game and the Bribery player attacked someone else