Yo! Finally got around to looking at this. Before I give any critical analysis, I should ask how the deck has been doing overall in some of the tournaments you have played or even more casual settings (if you play it at casual settings).

Are these also the cards you have purchased for the deck? If so, goddamn. An Imp Seal and all the original dual lands. Looks like you have really been beefing up this deck. Nice!

This deck is more of a thought experiment than something I play in tournaments (at least for the time being). If anyone played this in casual settings they are a coldhearted monster lol I planbon playing on cockatrice and I am slowly buying the paper cards for future use. Still a LONG way to go on that front.

The deck is incredibly consistent in playtesting. With my most recent changes the deck can combo off on turn 4 or earlier 90 percent of the time with at least 1 counterspell in hand 50-60% of the time (assuming I mullighan 1-2 times). If I cast Ad Nauseum in turn 2-3 I can usually combo off with 2-4 counterspells ready to be used the following turn.

Lilbrudder - What is the creature type you typically name with Cavern of Souls? Also, lands like Darkslick Shores, do they typically work in EDH? Do they backfire at all?

In EDH, especially in combo decks like this one, Cavern of Souls is usually used to prevent an important piece like your commander from being countered, in our case, Naga or Zombie.

Shaman is the most universally useful type, but honestly whatever creature I need to slam through at the moment is what I choose whether that is mage, druid, elf, or even bird. Its honestly way better in my Leovold deck, but cavern has such a powerful effect I pretty much autoinclude it in all my decks.

I have to say, this deck is inspiring me to build a similar Derevi deck. Thank you for all the ideas.

Anytime :-) when you finish it please send me a link. I've always been interested in Derevi.

Just saw your message a few hours ago so here I am.

Wow, i'm not sure what else I can suggest to add to the degree of optimization this deck already has.

I am particularly fond of Intuition and I think it is still worth a slot in the deck despite the drawback it presents. Since the deck seems to go all out for a really early win, Intuition or some other card that would facilitate in getting your combos out might be better suited in this deck than Nature's Claim. The same goes with Abrupt Decay but although I know it is pretty much an autoinclude in most decks.

I'll try to playtest the deck a bit and hopefully come up with better suggestions later.

Yeah I keep going back and forth on Intuition. I have probably included and cut it about 30 times over the lifespan of the deck lol. It is a really great card, but I have never found a way to consistently utilize it in Sidisi. I feel like it is one of those cards that is better the more you know about magic so perhaps one more attempt is due. I would love to cut Nature's Claim and Abrupt Decay, but since this deck gets shut down hard by Rest in Peace and Leyline of the Void I am hesitant get rid of either, but more tutors is rarely a bad thing and I also have Cyclonic Rift to clear the board in a pinch.

Do my descriptions seem relatively concise and clear to you?

Megalomania: The more I think about it the more Intuition feels like the right add. With Noxious Revival I can make Intuition piles of Necropotence and Ad Nauseam and be ensured of getting one of them the following turn for no additional mana. The same with Reanimate and Death and a handful of other combo pieces. I can also put opponents in the unenviable position of giving me Buried Alive or Food Chain without them knowing which is the combo I am actually going for. Intuition also fits nicely within my turn 3 win curve most games especially if I bait them into giving me the right card. Based on my current configuration it fits better than it ever has before. I knew asking you to look over the nearly finished product would yield good results. Thank you for the insight.

Be wary on intuition as you have to get 3 cards, so you will always want to pull revival with the other 2. Or regrowth depending on your ability to produce mana.

Always glad to help, buddy. Intuition works best with redundancies and recursion, both of which you have in abundance.

My oona deck was built around it before I started using Insidious Dreams.

The bigger question now is what to cut. You have a very good reason for keeping Nature's Claim and Abrupt Decay so I myself am now unsure if you can afford to lose those. Lol