I would remove some of the +1+1 counter generation, as while they are generally very powerful cards (eg: Forgotten Ancient ) They tend to be whiffs on Mayael's ability and otherwise tend to just sit and pump. Champion of Lambholt is slightly different as she affects board state, she does something while she's idle.

Overall it looks like it has a pretty solid start, though your land base seems a smidgin low, I would consider cutting out the mana rocks/signets and adding lands and ramp (access to green yay!), also by lowering your creature count you can increase the likelihood of getting the creatures you want (eg: I'd prefer to get a Ulamog, the Infinite Gyre over an card:Ulamog's Crusher). 30-35 is a solid creature count, as is 38ish lands.

I obviously have no idea about your budget/playgroup style, but my playgroup tends to have a ton a tutor/dig which makes the game a lot more consistent thing, though my other playgroup prefers few/no tutors and rely more on card draw or things like Summoning Trap (rather than Tooth and Nail ). Again all up to preference, but cards like Worldly Tutor can be real mean with Mayael as it more or less says, pay 7 play any creature with power 5 or greater from your deck.

Some other fun things to note!

Aggravated Assault or Bear Umbra + Hellkite Charger = have been known shenanigans in my playgroup.

Any creature with a landfall trigger Admonition Angel + Realm Razer = lots of triggers once he's gone.

Good luck with your deck and construction, Mayael is my favorite EDH deck I have at the moment. Here's mine if you're looking for more suggestions or something. deck:mayael-the-anima-derp-stomp-aggro

Oh, almost forgot, I love the hell out of Primordial Hydra , but I can't tell you how many times I used to use Mayael and hit him as one of the creatures and then cry that I couldn't play him. Just food for thought.

Oh, and forgive my ignorance on you bottom header, about lands/creature count.

goatsucker, you are forgiven; more than half of the people who comment don't read that part.

I like a lot of your suggestions. To tell you the truth, though, I'm not sure if I even want to continue with this deck. I've done some playtests, and it just isn't fun for me when I play it. I've been putting a lot more work into my Kaalia deck deck:wings-of-the-witch-suggestions-wanted, which is cruel for all of my opponents, but gives me sadistic glee when I play it.

Again, thank you for your suggestions, and I'll probably come back to this deck after I finish my Kaalia one. Your Mayael deck is awesome, btw.

Why thank you sir. I posted on your other one, just something kinda fun and cheesy, but rurrrr mean if it goes off.