Cavern of Souls maybe?

added Cavern of Souls, might dump Oracle of Mul Daya, not sure if she's really doing anything in this deck, other than the occasional land flip

Vigor

Vigor . Purity , and Lord of Extinction have all made the cut, and are now part of the deck

added planechase cards Last Stand , Maelstrom Wanderer , Fusion Elemental , Exotic Orchard

I've always been underwhelmed with Purity in EDH. Also, I find your lack of Sol Ring disturbing.

Purity might get dropped for a Sol Ring , so far Purity hasn't done much for me. I was gonna give it a few more tries before I abandon the poor unused elemental pegasus looking thing

Here's a link to my Horde of Notions deck: Zandl's Horde of Notions (Ideas? Suggestions?)

Feel free to pick and choose some cards and get some fresh ideas. If you want to know why something's in the deck, just ask.

I really need to work on a more stable and consistent mana base, without spending $400 on Rav duals. I think I'm getting there, though the Rav duals are in my list of purchases to eventually make. As for spells, I really prefer to run around 1/3 or more of the deck as creatures, I'm definately more of an agro player in edh.

I completely missed Slithermuse , Celestial Force , and Roil Elemental , I may have to find a way to fit them in. Skullmulcher , Lignify , and Minion Reflector just aren't doing enough actual work, so that might be three easy replaces

Maybe add Elvish Piper as another way to get some of the more mana-intensive creatures out early.

Elvish Piper is just kinda "meh" in EDH. As soon as it hits the board, everyone at the table realizes that you're now the biggest threats and will gang up on you.

Omnath, Locus of Mana seems like he would be at home (being an elemental and all) and he allows you to store mana for a later use if need be.

I Highly recommend Congregation at Dawn . You put a Maelstrom Wanderer on top and underneath an Avenger of Zendikar and underneath that a Primeval Titan = EVIL. You'll get a bunch of hasting +4/+4 Plant tokens along with 4 new lands that turn...

Incandescent Soulstoke , Liege of the Tangle , Living Inferno , Doomgape , Living Hive , Tyrant of Discord ...

A couple of ideas.

Hostility (I'm not sure if this card is allowed in this format though)

Reliquary Tower or anything that grants 'No Maximum Hand Size'. Maybe Spellbook .

I should prob try out the Tower, and maybe the Spellbook , or card:Venser's Journal. I looked at Hostility , but have been really undecided by the card. Vigor isn't quite working out for me, so maybe I'll try a different approach.

I'd never thought of the Congregation at Dawn idea, but it seems pretty good. Even if something gets countered, thats still 3 big threats to deal with. I'm sort of going back to the drawing board on my creatures, the elemental champions aren't working for me the way I want them too, though its good in theory...