I think that there are a few creatures in your deck that just seem less useful than your other ones, although I've only recently tried running a Mayael deck so consider my perspective limited.

Although Elvish Piper's ability is useful for this deck I find that usually the summoning sickness makes it too slow and it tends to get killed off before it can do anything. Hamletback Goliath really suffers from not having trample and usually just gets chump blocked until someone can kill it. Mycoid Shepherd is a decent body for its cost but the life you get from its ability tends to be of minimal value, so there is probably a creature with a more useful ability that you could put in that spot. As game changing as Novablast Wurm can be, without haste it tends to get killed off and it is rather counter productive to your deck's theme of dropping a bunch of big creatures to stomp your opponents out. Razia, Boros Archangel is fragile for its cost but I can see how it might be useful since it has haste. Rith, the Awakener's ability takes up mana that is usually better spent on Mayael's ability and casting your support cards. And I've always considered Titanic Ultimatum to be a "win more" card in a Mayael deck but that is just speculation on my part.

There are a few cards that I could recommend for your deck. Bloom Tender has worked well in my Mayael deck. Craterhoof Behemoth could replace Titanic Ultimatum. Iroas, God of Victory and Vigor help protect your big guys from deathtouch creatures. Sigarda, Host of Herons helps protect against Grave Pact and other sacrifice shenanigans. Spellbreaker Behemoth could replace Mycoid Shepherd and makes it easier to hard cast creatures past counterspells. Quicksilver Amulet could replace Elvish Piper (I know that it takes more mana to use but it survives wrath effects and can be used even if you are having mana color troubles).

SaberTech do you know what else I can take out for the suggestions you gave me?

Well, the number of cards I thought you should take out should match up to the number of cards I suggested that you could add, but the next few cards I would be inclined to take out of the deck would be: Magmatic Force (although its ability is good for keeping small utility generals under control), Mossbridge Troll (offers not utility to the deck but it does have a good chance to survive a wrath spell), and Mayael's Aria (I have played a number of games against Mayael decks but I can't say I've ever seen this cards really do much during a game).

I'm not sure what to take out after that. The non-creature spells left in the deck are almost all pretty standard support spells (although I do find Defense of the Heart to be unreliable) and your creature selection pretty much comes down to personal preference.

I could link you to my own Mayael deck if you are interested to see the route I took, but the list is a little outdated and your deck actually gave me a few ideas that I would like to try.

SaberTech I would like to say that I appreciate all of your suggestions! So far they are making the deck look a lot better. I do see that I should take out Magmatic Force, Mossbridge Troll, and Defense of the Heart. Anything else you could suggest that would be suitable replacements?

SaberTech I am interested in seeing what route you took.

I'm not sure what your price range is, but I would be inclined to suggest Scroll Rack to help manipulate your hand and the cards on top of your library, Sylvan Library for more library manipulation and card draw, and Worldly Tutor.

I also like using Survival of the Fittest, Genesis, and Sneak Attack in my deck but my version has more graveyard interaction than your does so I'm not sure how well those would work out for you.

My Mayael deck is Mayania.

SaberTech I don't have a budget

Oops, you already put in Sylvan Library, my bad. Siege Behemoth has worked out well for me as another way to help punch damage through. Or you could look at Soul of the Harvest to help with card draw.

SaberTech Thanks man! I do want to add Soul of the Harvest and Scroll Rack but am not sure what to take out.

Yeah, without some playtesting it's getting hard to tell what to cut. When I hit this point with my own decks I start looking at whether I have multiple cards that do similar things and removing the least efficient ones. You run both Spearbreaker Behemoth and Vagrant Plowbeasts but the Spearbreaker is definitely the better of the two so you could remove the Plowbeasts for Soul of the Harvest.

For Scroll Rack you could maybe remove either Green Sun's Zenith or Natural Order. The Zenith is useful early in the game to help you grab mana dorks but it doesn't help you cheat out your larger green creatures for cheap. Natural order can cheat out big guys, but requires you to sack another creature to do it, which can be costly since you don't have that many cheap creatures to begin with so it may require you to sac a large creature. The choice is up to you as to which one you think matches your play style better. The reason why I think Scroll Rack should replace one of these tutors is because your deck benefits more from being able to repeatedly put creatures that get into your hand back onto the top of the library than it does from being able to tutor up and put one creature onto the battlefield.