doctorhydrogen

Ah, that's right, I remember thinking that when she was spoiled.

Sure you take damage, but a Primal Surge would just auto-win here.

If you're saccing the monkey on the reg why not throw a Skull Clamp on him first and get some cards.

I'm of the mind Outpost Siege should be in any red deck. It's red's Phyrexian Arena.

Here's the secret about Kaalia; she's really not very good if you play with reasonably intelligent people. She's cool and I absolutely get why people like her, but if your group has any brains at all they'll just stick her to the board with a Darksteel Mutation or whatever and go about their day while you try to hard-cast 9 cmc angels/demons/dragons. All that said, since you're rolling with her here's what I'd fix:

General stuff:

You need a ton more draw. Having a lot of dudes in the deck is less important than always having one in your hand, and just having creature density and hoping you top-deck one isn't enough. I'd find room for Night's Whisper, Sign in Blood, Read the bones, Ancient Craving, Ambition's Cost and maybe even Promise of Power. You want between 7-10 reliable draw options in Kaalia, minimum. She's just gonna run out of gas otherwise.

Specifics:

Fervor is probably unnecessary. Just run Hanweir Battlements or Flamekin Villiage and save yourself a slot.

Griselbrand is banned in EDH.

You have two copies of Tariel.

While it's probably a meta issue, I've largely abandoned Darksteel Plate. In the last couple years alone we've seen Utter End, Anguished Unmaking, Declaration in Stone, Imprisoned in the Moon, Song of the Dryads, and Darksteel Mutation, all of which get around it. And Swords to Plowshares, Path to Exile, Condemn, Crib Swap, Chaos Warp, etc. all still exist. There's just too much tuck/exile/lock stuff to count on indestructible to save Kaalia. Lightning Greaves would be loads better.

IMO any three color deck should be running Chromatic Lantern, City of Brass and Mana Confluence. The fixing is too good.

IMO any deck running black should have an Urborg, Tomb of Yawgmoth. The fixing is too good.

Akroma's Memorial, while a bomb, feels like overkill in a deck where your dudes almost all already have a ton of abilities. And it's just one more huge thing you have to try to hard cast.

Righteous War is Kaalia's best friend. It gives her protection from 95% of removal in the game.

I like Revoke Existence just fine, but for one more mana Chaos Warp deals with literally any threat at instant speed. The versatility is just too strong to not run.

You've got two copies of Asceticism.

I'd much rather run Natur'es Lore than Explore in that slot.

Generally speaking I think 32 dudes in a deck not taking advantage of it in some way is too many. You're asking to overextend. IMO either add even more guys and run stuff like Lurking Predators and Wild Pair and Genesis Wave/Primal Surge with a haste enabler (Concordant Crosswords/Akroma's Memorial) or ratchet it down a bit for utility.

Hall of Gemstone is pretty mean in mono-green as it doesn't hurt you at all and can lock some decks totally out of playing. I'd replace Tooth and Nail, just because I hate that stupid skill-less card :)

One control option here is to run all snow lands, and Glacial Crevasse. Having an on-demand fog in the event of an alpha strike that doesn't require you to keep mana up is really, really useful.

This is probably entirely meta-dependant, but I found that you spend seven mana (your entire turn generally) casting Vorinclex, and he/you become target #1 and he doesn't survive a spin around the board before you can use his mana doubling. Where as Sheoldred, Elesh Norn and Jin Gitaxis pretty much start screwing people right away, there's just too much time for Vorinclex sitting there not getting work done to justify. I've pulled him out of the deck where I ran him for that reason.

That might be totally not true in some environments.

I'd be really tempted to run Crop Rotation. Between Nykthos and Cradle you have two gross targets.

It's kind of mean to the point where I stopped running it in mono-green, but Hall of Gemstone just shuts down some decks, and it stops countermagic from hitting you.

You probably want Polymorph here. Turning a drake into a Guile or Consecrated Sphinx while making a drake seems like a good deal for four mana.

Enchantment decks live and die by draw. I'd find room for Verduran Enchantress, Argothian Enchantress, and Eidolon of Blossoms, and probably and Sram, too. There's zero situations where you're gonna be like "Oh snap, Orchard Elemental! GG motherf*cker!" but drawing six more enchantments off your Enchantress after playing six just ends people. I'd run literally nothing but "when you play an enchantment draw a card" dudes in my Sigarda deck if they made 14 more of them.

Nature's Lore all day over Lay of the Land. 1 more colorless mana to put the land into play untapped is gold.

Sphere of Safety > Norn's Annex in this deck.

Ethereal Armor can get out of control fast.

Shield of the Oversoul would be gross here.

Greaves are in there, plus there's Asceticism for added protection. What I've mostly found though is that there are just other scarier threats. Yeah, someone could Swords Reki or something, but then they wouldn't have it for that Tasigar or Proosh next turn. Denying me a couple of cards is less a priority than keeping other scarier things in check unless someone's holding three removal spells or something.

It's the sideboard card (and title).

Hero's Downfall > Murder. Same CMC and it hits Planeswalkers.

Exsanguinate would do good work.

Cabal Coffers would be great here, though it's getting a bit pricey. Nykthos, Shrine to Nyx absolutely would work here.

Sylvan Safekeeper is usually your 1 mana tutor as it keeps Yisan safe.

I liked Gyre Sage as my 2 mana tutor as it gets out of control fast with Yisan.

Five counters is where you would need to spend a little money, because Seedborn Muse just ends the game. Nobody knows it yet, but it's over since now you can use Yisan on everyone's turn, and he can't be targeted due to Sylvan Safekeeper.

Six drop Soul of New Phyrexia makes your dudes indestructible, but you already have that in here.

Seven drop Hornet Queen is fine, though Avenger of Zendikar is probably a bit better.

Eight drop you play Craterhoof Behemoth, kill 6 people simultaneously, and get bored of playing Yisan because the deck plays the same every time :)

If you don't want to go that route since Muse and Craterhoof are both over 20 may I suggest replacing some of your sorceries with permanents that let you do the similar stuff, then run Primordial Surge to drop 70 permanents at once for an alt win-con?

If you want to run a neat, wierd card you can cast Panglacial Wurm while tutoring with Yisan.

42 lands is more than you need in a two color deck. I run 37 in Glissa, but even if you want to be conservative 38 would be plenty.

Executioner's Capsule comes back to your hand with Glissa whenever you kill something with it. Same for Triangle of War to a lesser extent if you're using deathtouch dudes or beaters to fight.

Tidy Conclusion seems like a lot of mana to gain what is probably an irrelevant amount of life.

Without running a Mindslaver lock it seems like Forbidden Orchard is just helping people have tokens to sacc to your edicts. I'd just run Tainted Woods there.

Crystal Vein works nicely with Gitrog, particularly with a Crucible around. Inventor's Fair works nice here too as a way to grab Crucible (then recast the Fair).

Depala vehicles, dig it.

I don't like tempo-hit fetches like Evolving Wilds and Terramorphic Expanse in a two-color deck unless you really need landfall triggers or shuffle effects, which doesn't appear to be the case. The single life from Windscarred Crag is likewise meaningless, and Boros Guildgate brings nothing to the table. I'd put Temple of Triumph in one of those slots for sure.

There's almost no downside to running Hanweir Battlements, and there's times the haste trigger can win a game late.

Even though Depala has draw baked in, I'd still slot in Outpost Siege. It's one of your best draw options in Boros.

Oblivion Ring or even Banishing Light are all better than Caught in the Brights. They do more to more targets for the same mana.

Dispatch would do good work in this deck.

Sage isn't the two-drop from hand, he's the searchable two-drop (as in two counters) after Sylvan Safekeeper at one. But even if you're playing it from hand on turn two if you happen to miss a mana dork he's still probably going to get out of control. I never regretted having it.

I wrote Sylvan Safekeeper as the five drop, but meant Seedborn Muse hitting at your five-counter search is when the game ends. Everyone else just doesn't know it yet. Well technically it's on the next player's turn when you drop Soul since your stuff is now untargetable and indestructible, but Muse is what makes it happen.

Meh on Hornet Queen. If you need to be blocking lethal that early you've done something wrong. That said, more often than not the Hornet Queen tokens are enough to win in a 3 player game off Craterhoof. Not sure the math is there to do it in four, and for sure not in five.

Wurm is just an extra piece to guarantee the win. It's even more necessary here since you are limiting yourself to four tokens off Hornet Queen vs. 6-8 off Avenger. Plus you're going to have the mana free thanks to Gyre Sage and Seedborn Muse, again, unless you're doing something wrong.

Oak Guardian comes at the wrong point in the curve to win unless you're in a three player game. I mean it's useful to have in the deck since there will probably be times where at six counters you can grab it and kill the board instead of grabbing Soul and killing them thirty seconds later at eight counters, but you can't rely on it being there unless you plan to somehow remove counters from Yisan or skip fetches.