Very cool deck list. I plan on building something similar list in the near future.
Since you are running a token theme and Ob Nixilis, Unshackled, have you considered including Fertilid, as part of your mana fixing package. I think Fertilid is a strong card on its own, but the ability to turn Fertilid into a Pay 2, target opponent loses 10 life and sacs a creature, with Ob, Nixilis on the field would be too fun.
I'm running a Teneb deck right now that tends to generate more mana than I need.
These are the current mana-sinks I'm trying out, and I mention these because no one else has Vizkopa Guildmage - Mostly dealing combat dmg to win. So I thought this would be fun to activate the second ability multiple times Drana, Kalastria Bloodchief - Nom nom nom. Exsanguinate - A feel bad instant win... if the blue mage doesn't have a counter.
If you really need ways to donate/trade permanents, then check out Donate, Juxtapose, Vedalken Plotter. Personally, I find the best cards to donate are enchantments (e.g., Nevermore, Oblivion Ring), and spent mana-rocks (e.g., Sphere of the Suns), instead of cards that just piss people off.
Also, I don't know how much mileage your getting out of Void Stalker, kinda seems like and expensive tuck. Consider Hinder, or Unexpectedly Absent. Both can be used to tuck Commanders, but at instant speed. Keep in mind you can cast Unexpectedly Absent for x=0, in response to someone tutoring/searching their deck.
First a questions. I'm a bit skeptical about what Jarad does in this deck (aside from set the theme and colours). I see some good interactions i.e. Hatered pump then sac with Jarad to win, or in second main after playing craterhoof. Anyways my point/question do you find that you actually use his ability? or is this more of an after-thought?
Also, since you don't have that many zombies maybe Phyrexian Arena in place of Graveborn Muse . I think on average you would be better off with the Arena since it is less vulnerable to removal. Then again maybe not.. but its something to consider.
All in all cool build, I've been looking for something to do with all the elves in my trade binder since I took apart my Edric deck, I may have to build something similar. Cheers.
Archaeomancer : too slow, if you can replace it with a snapcaster.
Lavinia of the Tenth : depends on your meta but this wont stop most EDH level threats
Skullclamp : Not enough clamp targets. I love this in Elves or in Karador. Since I have 1/1s or stuff to sac. But I dont see enough guys in this list that I'd want to 'die'
Body Double: I think his guy is better in re-animator decks since you know your best cards will be in the graveyard... that said if there are a lot or re animator decks in your meta then reconsider.
Kor Cartographer : too slow even with the ETB, consider weathered wayfarer or land tax
I don't think you have enough ways to make Brago connect for combat dmg. As an opponent its a no brainier to block Brago *at all costs* if your going to get all sorts of great ETB triggers. Don't give your opponent the choice.
Also, i've always wanted to play Decree of Silence, it seems like Brago may be a home for it, since you could potentially remove the depletion counts from it each turn. Good times.
Since you are running a token theme and Ob Nixilis, Unshackled, have you considered including Fertilid, as part of your mana fixing package. I think Fertilid is a strong card on its own, but the ability to turn Fertilid into a Pay 2, target opponent loses 10 life and sacs a creature, with Ob, Nixilis on the field would be too fun.
Also, Abzan Ascendancy seems like a strong card in this theme.
These are the current mana-sinks I'm trying out, and I mention these because no one else has
Vizkopa Guildmage - Mostly dealing combat dmg to win. So I thought this would be fun to activate the second ability multiple times
Drana, Kalastria Bloodchief - Nom nom nom.
Exsanguinate - A feel bad instant win... if the blue mage doesn't have a counter.
Other options for Junk colours
Geth, Lord of the Vault
Genesis Wave
Debt to the Deathless
Mind Over Matter + (Temple Bell or Otherworld Atlas), will help with your win-cons Niv-Mizzet, the Firemind and Psychosis Crawler. and obviously helps you look through your library
How about Purphoros, God of the Forge, has great interaction with with Assemble the Legion and Dovescape
If you really need ways to donate/trade permanents, then check out Donate, Juxtapose, Vedalken Plotter. Personally, I find the best cards to donate are enchantments (e.g., Nevermore, Oblivion Ring), and spent mana-rocks (e.g., Sphere of the Suns), instead of cards that just piss people off.
Also, I don't know how much mileage your getting out of Void Stalker, kinda seems like and expensive tuck. Consider Hinder, or Unexpectedly Absent. Both can be used to tuck Commanders, but at instant speed. Keep in mind you can cast Unexpectedly Absent for x=0, in response to someone tutoring/searching their deck.
With access to Necromancy and Prophet of Kruphix, I have two ways to play it at instant speed. It may not win games but will be fun to resolve.
Hes not a finisher but hes a great roadblock. In a tutor and combo heavy meta, it may just be enough to slow people down and soak up removal.
Ranger's Path -> Skyshroud Claim (or Culitvate or Kodama's Reach)
Verdant Haven -> Fertile Ground (there are others at 2cmc but cant recall the names)
Sundering Growth -> Beast Within (for one more mana it can hit anything you need it to)
Fated Retribution -> Wrath of God, Austere Command, Catastrophe Rout, Phyrexian Rebirth, Winds of Rath
If you are having trouble with fliers consider more removal, Swords to Plowshares, Path to Exile, Condemn
As for suggestions since you have a good number of ETB why not Sheoldred, Whispering One?
Also, since you don't have that many zombies maybe Phyrexian Arena in place of Graveborn Muse . I think on average you would be better off with the Arena since it is less vulnerable to removal. Then again maybe not.. but its something to consider.
All in all cool build, I've been looking for something to do with all the elves in my trade binder since I took apart my Edric deck, I may have to build something similar. Cheers.
Archaeomancer : too slow, if you can replace it with a snapcaster.
Lavinia of the Tenth : depends on your meta but this wont stop most EDH level threats
Skullclamp : Not enough clamp targets. I love this in Elves or in Karador. Since I have 1/1s or stuff to sac. But I dont see enough guys in this list that I'd want to 'die'
Steel Hellkite: Great card, but off theme, no ETB.
Body Double: I think his guy is better in re-animator decks since you know your best cards will be in the graveyard... that said if there are a lot or re animator decks in your meta then reconsider.
Kor Cartographer : too slow even with the ETB, consider weathered wayfarer or land tax
Things id consider.
Steel of the Godhead
Unquestioned Authority
Parallax Wave, to remove blockers, then bounce it reset the fade counters then do it again next turn.
Also, i've always wanted to play Decree of Silence, it seems like Brago may be a home for it, since you could potentially remove the depletion counts from it each turn. Good times.