consider putting in things like Mana Reflection and Mirari's Wake because more mana means more slivers. I would also like to see a Boundless Realms in there because holy crap slivers get scary when you have enough mana to put three or four out each turn.

It's tempting to try and stuff the deck with tons of slivers because you think that more slivers is better. But for vanilla slivers, Sliver Queen is already sufficient. along those lines you should consider taking out Two-Headed Sliver , Toxin Sliver , and Striking Sliver , as well as many other of the ones with weak abilities ( Shifting Sliver makes those three unnecessary.) if they can't block, first strike and deathtouch are meaningless more or less

@ jaminfine: I could see either Mana Reflection or Mirari's Wake in here, I currently run Wake in 3 other EDH decks actually. Problem is just finding them for trade. Currently trying to find a spot for Garruk, Caller of Beasts too as in a themed deck such as this is where he can really shine.

Boundless Realms wouldn't be worthwhile IMO because there are currently only 14 basic lands, and it's a 7cmc spell. For 7 mana I could potentially combo off or drop 2-3 spells. Being that this is a 5-color deck, a majority spread of non-basic lands is a must. While I don't have shocks and the like for it, the consistency would likely suffer if more basics were added.

Two-Headed Sliver - noted, was just in there as a cheap sliver.

Toxin Sliver - helps deal with regeneration if I pull it, let alone that I can block with 1/1 slivers from Queen and wipe their board. As a 3/3 with better deathtouch for 4cmc, I think it's worth it's weight if I can't tutor for Shifting.

Striking Sliver - again, there as a cheap sliver so as not to have the average card cost be 4+. Adding Garruk 3.0, Mana Reflection and Mirari's Wake will bog the deck down with higher casting costs.

I'll playtest it with at least 2 of the 3 cards mentioned above and see how it works. People's gut reaction to Slivers is to kill them quick before they establish a board, cheap creatures help mitigate that a bit. Having Sliver Overlord out with Training Grounds is basically good game. Fetch any combination of Queen, Manaweft/Gemhide, Blur, Root, Quick? and you take the board over in a turn. Then flash in Legion and it's over.

do you think there could be room for mutavault

@joxer0705 - Honestly, no. Mutavault doesn't benefit the ETB slivers, and hitting 5 colors as soon as possible is huge. Even with a manaweft/gemhide sliver out, the color fixing effectively makes it a Rupture Spire, which is awful.

This version of the deck wants to combo out asap. A more aggressive version of the deck with Hivelord or Legion at the helm might want the extra body badly enough to run the colorless land. As is, I can't afford it, otherwise I would.

I'm curious why you are not running a Sol Ring in the deck. I understand that you're looking for colored mana, but you have an Urza's Incubator which effectively does the same thing as a sol ring except its only for slivers and costs instead of .

Also, I hate the card Cascading Cataracts because you have to tap 6 lands for 5 mana and while I ran it I had multiple times where it was my 5th land and I still couldn't cast my commander. If it works for you that's great but I have had multiple bad experiences with it.

@The_Munchkin: Sol Ring's exclusion was less of an oversight and more of a "I shouldn't need it" at the time when I originally made the deck. Colored mana production was at a premium, but I'm open to trying it out and cutting one of the redundant slivers like Essence Sliver to see if it's impactful enough. (it's likely to be)

Cascading Cataracts is there as a means of making 5 colors in the event that the Magic gods have seen fit to screw me on colors, but I still have access to enough mana to make use of the land and get the 5 I need. While not having all 5 colors by turn 5 is a rarity, it's insurance for that, if nothing else.