Depending on the situation, Slithermuse can be very efficient card draw, usually netting you at least two cards.
With the number of CIP creatures you run, Crystal Shard is a must-have.
Also, this seems kinda random, but would Batwing Brume help you against anything? It really depends on whether you face up with token/swarm decks often.
Desert Twister costs too much; I'd take it out, or replace it with Utopia Vow or Lignify (which Treefolk Harbinger can grab). While it can destroy any permanent, it costs far too much at 4GG, and you can already consistently
Erratic Portal, in my opinion, probably won't do much. AT most, it means that your opponents might need to keep an additional mana open. This normally wouldn't automatically mean it shouldn't be in the deck, but I really can't see much else you could cut out. There's just too much good stuff.
This is almost exactly how I would have made it; however, Crucible of Worlds is banned in EDH, unless your group is cool with it. Overall, I only have a few suggestions.
Are Bloodghast and Reassembling Skeleton enough to support Contamination? I'm not sure myself; I'm just bringing it up.
What exactly do you use Worldslayer for? i.e., what's your recovery plan?
Unless there's some quirk in your playgroup that makes them worthwhile, I'd recommend getting rid of Daze, Force Spike, Miscalculation, Rune Snag, Mana Leak, and Spell Pierce and replace them with things like Glen Elendra Archmage and Rebuff the Wicked. As a general rule, "soft counters" are not very good in EDH. Of course, if you have some reason for this that eludes me, by all means leave them in.
Considering you have two artifacts, both costing 3 or less, Mishra's Workshop kinda seems narrow and excessive. I hope you didn't buy one just for this.
I'd suggest using repeatable token creation instead of one-shots. Bearscape and Imperious Perfect seem like good cards for this. Along those lines, Mass Polymorph, considering the number of tokens you have, should be played alongside Polymorph. You'll probably grab all three of your fatties.
Overall advice, though, is play bigger spells. You certainly have the manabase to support it. A lot of the cards here are fine in a normal deck, but here you have more time to set up and get mana. For example, try Recurring Insight instead of Lat-Nam's Legacy.
It might be worth mentioning that you lose to most of these cards. I'm not entirely sure if your counters will protect you from that kind of thing, but maybe they will.
Despite all of the above, I think the deck is a cool idea and probably pretty powerful. Good luck!
EDIT: Additional thought, considering your three tutorable creatures have flying, maybe you'll want to try out Moat? Worth a shot, IMO.
- cards are legal as of their set's prerelease
- Shahrazad is legal for play in EDH"
From the website.
Ante cards are not legal in EDH.
Huh, I guess they're just bad where I play. Well, this is the kind of thing that makes EDH great.
Agree with Throst54 on the wincon, though.
Eternal Witness is a good card even without any kind of copying abilities, but here it's great.
Sensei's Divining Top is also a staple, and worth the money. With the kind of ramp you have, I bet Planar Portal would work well here.
Frontier Guide and Journeyer's Kite aren't quite along the same lines as your other mana acceleration, but they generally won't make anybody mad.
Flameblast Dragon is just an amazing beater. Try it.
That's about it for my ideas, but that really seems cool.
Yet. There can be no nonpermanent token for this spell to target yet. :Rubs hands together in an evil-looking way:
What I mean is, you can never be too careful with these things.
With the number of CIP creatures you run, Crystal Shard is a must-have.
Also, this seems kinda random, but would Batwing Brume help you against anything? It really depends on whether you face up with token/swarm decks often.
Erratic Portal, in my opinion, probably won't do much. AT most, it means that your opponents might need to keep an additional mana open. This normally wouldn't automatically mean it shouldn't be in the deck, but I really can't see much else you could cut out. There's just too much good stuff.
Are Bloodghast and Reassembling Skeleton enough to support Contamination? I'm not sure myself; I'm just bringing it up.
What exactly do you use Worldslayer for? i.e., what's your recovery plan?
Steel Hellkite will be a huge help killing noncreatures. Huge. Drana, Kalastria Bloodchief kills creatures and can be lethal with a Grafted Exoskeleton.
Precursor Golem has me baffled. It doesn't seem like you have many targeted instants and sorceries. I'd cut it.
But seriously, your deck seems pretty awesome. If you can afford it, go for it.
Considering you have two artifacts, both costing 3 or less, Mishra's Workshop kinda seems narrow and excessive. I hope you didn't buy one just for this.
Crystal Ball is far superior to Impulse; also, might I suggest Soothsaying?
I'd suggest using repeatable token creation instead of one-shots. Bearscape and Imperious Perfect seem like good cards for this. Along those lines, Mass Polymorph, considering the number of tokens you have, should be played alongside Polymorph. You'll probably grab all three of your fatties.
Overall advice, though, is play bigger spells. You certainly have the manabase to support it. A lot of the cards here are fine in a normal deck, but here you have more time to set up and get mana. For example, try Recurring Insight instead of Lat-Nam's Legacy.
It might be worth mentioning that you lose to most of these cards. I'm not entirely sure if your counters will protect you from that kind of thing, but maybe they will.
Despite all of the above, I think the deck is a cool idea and probably pretty powerful. Good luck!
EDIT: Additional thought, considering your three tutorable creatures have flying, maybe you'll want to try out Moat? Worth a shot, IMO.