I absolutely love Mayael, I've been playing her as my commander since she was printed and have never grown tired of her. Best advice I can give anyone trying to build a Mayael deck is to ignore her in play testing. It's really easy to fall into magic Christmas land mentality with her and think that you're going to get all these really expensive creatures for cheap, and you can. But you can also just run her into a lightning bolt then sit there doing nothing while you stare at these 9 and 10 cost creatures you'll never be able to cast. Mayael is very fragile and if you're not working really hard to protect her or ramp to the point where you can cast your fatties then 25-30% of your deck can just be dead draws which is a huge draw back.
My list is mostly tuned for 1v1, using the French ban list, but I think it shows this idea really well. It plays really aggressive even without casting Mayael and gives you a lot of flexibility to decide when to cast her and start using her ability to pull ahead with card advantage.
Lands and Ramp
Because of my reasonably low cost fatties I'm able to ignore the large ramp spells that are really common in EDH. I try to avoid ramp spells that cost more than 2 so I can cast Mayael on three and activate her on turn 4-5.
Knight of the Reliquary, Weathered Wayfarer, Crop Rotation, Woodland Bellower and the three hideaway lands: I wanted to avoid running things like Quicksilver Amulet but I still wanted to get the Mayael effect when Mayael was being locked down. Knight and Wayfarer do a fair impression of Mayael when combined with the hideaway lands while still having a lot of other utility when you don't need that effect out of them. There is also a Gruul Turf to reset a bad hideaway when you need it.
Budoka Gardener
: This is a recent addition to the deck, so I'm still not sure it justifies the slot, but the idea is to give me another ramp card that also can do an imitation of Mayael when I no longer need to ramp. It's important to note that you don't have to put a land into play to flip him, you just have to control 10 lands when the ability resolves.
Gyre Sage: Between this guy and Knight of the Reliquary your ramp can also can get really big. This is probably my favorite T2 play. He makes a lot of mana, and when I don't want that mana anymore he gets really rowdy.
Contested Cliffs, and Kessig Wolf Run: These lands have very different effects but I wanted to point them out because I think they are very important. Kessig closes out games like you wouldn't believe. I very rarely use it's effect without killing a player, and it is also one of the easiest ways to win the game with Mayael's Aria. Cliffs on the other hand gives you a repeated source of removal, which is great, and it gives you some controlled responsiveness when the mana you left up for Mayael needs to be used on something a little less random. I'll go into detail on this later.
Card Advantage
One of the things that makes Mayael so great is that she applies consistent card advantage and constant pressure. So why not run more card advantage!
Soul of the Harvest, Elemental Bond: These are really straight forward, but important. Drawing an extra card for each creature is great. Keeps your hand full to recover after wrath and keep the pressure on.
Cream of the Crop, Sylvan Library: These two enchantments go a long way to smoothing out your draws so you don't get gummed up with fatties stuck in hand, while also giving you extra control over what you're hitting when you activate Mayael.
Rishkar's Expertise: This is a recent addition to the deck. It used to be Greater Good but I found that card to be a little awkward. Considering the low cmc of this deck, it's not to difficult to find something sweet to cast for 5 mana and keep the pressure on.
Removal
I'm still tinkering around with finding the right balance here, but I've found that I don't generally benefit from running wraths and I really like having flexible instant speed removal. As a result most sorcery speed answers come close to the chopping block any time I find something that lets me get 2-for-1 at instant speed.
Bind: Probably the strangest card on my list. Since I keep 6 mana up on my opponents turns I wanted to be able to take a page out of the blue playbook every once in a while and say no. I originally was considering trying Lapse of Certainty in this slot, but the cards I want to stop most are infinite combos, like Kiki-Jiki, Mirror Breaker, and artifact wraths, like Oblivion Stone, both of which are very popular in my local meta.
Dromoka's Command, Wear//Tear, Shattering Pulse, and Oblation: These are exactly what I want in my removal, instant speed and flexible. Being able to take out multiple targets while keeping up Mayael mana is great. Oblation lost a little bit of strength when the commander tuck rules were changed, but it is still very strong. You can tuck one of your own cards and draw two in response to a wrath/removal spell to give you a little more juice to keep up the pressure as well as removing most target-able permanents on the other side of the table.
Naya Charm: While fairly weak on the removal scale, the flexibility of this card should not be underestimated. It does a good job of taking out early drops and utility creatures while also filling a regrowth slot and a sudo overrun slot.
Decimate: I absolutely love this card, but it can be a dud sometimes. When you are missing a permanent type it is useless, but when it is turned on you feel like a champion. It might be on the way out when I find an instant that can fill this spot satisfactorily.
The Fatties
So this is why we play Mayael. The big creatures. I generally want two things out of the creatures that make this list. I want to be able to cast them if they make it into my hand, and I want to get some value out of them beside their body. This can be an ETB effect, LTB effect, or a powerful static effect.
Rage Nimbus, and Rhonas the Indomitable: These are probably the weakest cards to hit on Mayael, but do not underestimate them. Both of these trigger your ETB enchantments for cheap in the late game. It's not uncommon for me to cast one of these when I hit 9 mana and still keep mana up for Mayael, which can be a huge tempo swing.
Angel of Serenity, Bogardan Hellkite, Gruul Ragebeast, Terastodon, Woodfall Primus: These are the guys that double as removal. They are the backbone of the deck and every time I remove one I regret it. Ragebeast is the strongest by a mile.
Kazuul, Tyrant of the Cliffs, Wurmcoil Engine: Being the Mayael deck, I want to be the king of combat. As a result you'll see a lot of life gain in the list as well as keywords that give me an advantage in combat. Cards like this give me the freedom to push my troops into the red zone while keeping my life total high.
Spellbreaker Behemoth, Dragonlord Dromoka: On the other end of the spectrum you need something to give you resilience to the control player. As a result there are a lot of guys in the list that protect you from removal, but these two make sure your creatures hit the board when you cast them. Between these and Mayael, counter spells can be very weak against you.
Greater Gargadon, Eternal Dragon, Krosan Tusker, Shefet Monitor: These guys really smooth out your draw, having large creatures to Mayael in that also give you this level of flexibility when you draw them is great. If I could find 2-3 more creatures that I could cash out for an effect when I draw them early, but still have a good board presence when I hit them with Mayael, I'd be really happy.
Gisela, Blade of Goldnight, Purphoros, God of the Forge: When you want to close out a game, few cards do so quicker than these two. I mostly wanted to point these out to contrast them with the omission of Craterhoof Behemoth. On paper Craterhoof seems like a shoe in, but in practice I would mostly Mayael at the end of my opponents turns, which made Craterhoof a vanilla 5/5 off the top.
Finishers
Most of the time you win by turning your creatures sideways. But it's nice to have a way to push through when that's not working.
Mayael's Aria: Sometime you just can't attack to win, so it's nice to have a card that says win the game. The counters and life gain are nice too.
Insurrection, Titanic Ultimatum: Insurrection is what Craterhoof wants to be in this deck. With the added benefit of also removing any blockers. Ultimatum is the preferred Overrun variant because of the lifelink and first strike. Which makes blocking nearly impossible and any crack back survivable.
Gameplay
One of the fun things about this deck is it's flexibility. So it's hard to write a turn by turn guide because what you prioritize will change depending on what your opponent plays.
Mulligans: Most mulligan decisions are pretty straight forward, you want a mix of lands and spells. Just avoid the all mana ramp hand and you should be good, that hand is a trap. This list is reasonably light on the ramp because it doesn't really need it.
Early Turns: These turns are mostly dedicated to trying to get some form of card advantage engine started while playing a little bit of ramp. Unless there is a good reason not to I'll run Mayael out on T3 in the hopes of activating her on 4-5. But in the likely scenario that she get killed, let her stay in the commander zone till you've worked through most of your opponent's removal.
Mid to Late Game, w/ Mayael: So you ran Mayael out there and got to untap. Now you get to play a lot like a control deck. Draw your card, play a land, and pass the turn. The only board state where it is potentially better to activate Mayael on your turn is when you have a Xenagos, God of Revels in play. Otherwise, use your instant speed creatures to make it difficult for your opponent to make good decisions on their turn. Attacking into an untapped Mayael is nearly impossible.
Mid to Late Game, w/o Mayael: So you didn't get to untap with Mayael. Leave her in the command zone. This deck isn't really interested in investing 5 mana in a 2/3. Prioritize card advantage engines to make up for her absence and start running guys out there. Your guys generally have a pretty high resilience to removal, and this is on purpose. You want to wear your opponent out of removal. Be careful not to over commit into wraths, but generally two creatures put on enough pressure in this deck to warrant an answer, so you don't really need to commit that much to the board to gauge how much removal your opponent has. Once the coast is clear, try running Mayael out there again and really put the pressure on.
